This gene encodes the beta subunit of casein kinase II, a ubiquitous protein kinase which regulates metabolic pathways, signal transduction, transcription, translation, and replication. The enzyme is composed of three subunits, alpha, alpha prime and beta, which form a tetrameric holoenzyme. The alpha and alpha prime subunits are catalytic, while the beta subunit serves regulat... See more...

Aliases for CSNK2B Gene

Aliases for CSNK2B Gene

  • Casein Kinase 2 Beta 2 3 5
  • Casein Kinase 2, Beta Polypeptide 2 3
  • Casein Kinase II Subunit Beta 3 4
  • Protein G5a 3 4
  • CK II Beta 3 4
  • Phosvitin 3 4
  • CK2N 3 4
  • Ckb1 2 3
  • Ckb2 2 3
  • G5A 3 4
  • Alternative Name: G5a, Phosvitin 3
  • Casein Kinase II Beta Subunit 3
  • CSNK2B-LY6G5B-1072 3
  • CSNK2B-LY6G5B-1103 3
  • CSNK2B-LY6G5B-532 3
  • CSNK2B-LY6G5B-560 3
  • CSNK2B-LY6G5B-562 3
  • POBINDS 3
  • CSNK2B 5
  • CSK2B 3
  • CK2B 3

External Ids for CSNK2B Gene

Previous GeneCards Identifiers for CSNK2B Gene

  • GC06P031698
  • GC06P031403
  • GC06P031737
  • GC06P031741
  • GC06Pf31767
  • GC06P031633
  • GC06P031419
  • GC06P031666
  • GC06P031711
  • GC06P032315
  • GC06P032503
  • GC06P032609
  • GC06P033402
  • GC06P031770
  • GC06P031779
  • GC06P031789
  • GC06P031882
  • GC06P031933
  • GC06P032000
  • GC06P032182
  • GC06P032214
  • GC06P047308
  • GC06P049355

Summaries for CSNK2B Gene

Entrez Gene Summary for CSNK2B Gene

  • This gene encodes the beta subunit of casein kinase II, a ubiquitous protein kinase which regulates metabolic pathways, signal transduction, transcription, translation, and replication. The enzyme is composed of three subunits, alpha, alpha prime and beta, which form a tetrameric holoenzyme. The alpha and alpha prime subunits are catalytic, while the beta subunit serves regulatory functions. The enzyme localizes to the endoplasmic reticulum and the Golgi apparatus. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2013]

GeneCards Summary for CSNK2B Gene

CSNK2B (Casein Kinase 2 Beta) is a Protein Coding gene. Diseases associated with CSNK2B include Poirier-Bienvenu Neurodevelopmental Syndrome and Autosomal Dominant Non-Syndromic Intellectual Disability. Among its related pathways are Adherens junction and Pathways of neurodegeneration - multiple diseases. Gene Ontology (GO) annotations related to this gene include identical protein binding and signaling receptor binding.

UniProtKB/Swiss-Prot Summary for CSNK2B Gene

  • Regulatory subunit of casein kinase II/CK2. As part of the kinase complex regulates the basal catalytic activity of the alpha subunit a constitutively active serine/threonine-protein kinase that phosphorylates a large number of substrates containing acidic residues C-terminal to the phosphorylated serine or threonine (PubMed:11239457, PubMed:16818610). Participates in Wnt signaling (By similarity).

Tocris Summary for CSNK2B Gene

  • Casein kinase II (CK2) is a constitutively active, ubiquitously expressed serine/threonine protein kinase thought to have a regulatory function in cell proliferation, differentiation and apoptosis. CK2 functions as a tetrameric complex with 2 regulatory and 2 catalytic subunits.

Gene Wiki entry for CSNK2B Gene

No data available for CIViC Summary , PharmGKB "VIP" Summary , Rfam classification and piRNA Summary for CSNK2B Gene

Genomics for CSNK2B Gene

GeneHancer (GH) Regulatory Elements Pubs

Promoters and enhancers for CSNK2B Gene
- Elite GeneHancer and/or Elite GeneHancer-gene association Download GeneHancer data from 2017 publication | Request up-to-date GeneHancer data (full dataset)

GeneHancers around CSNK2B on the GeneHancer Hub at the UCSC Golden Path

Cistromic (ChIP-Seq) regulation report from SPP (The Signaling Pathways Project) for CSNK2B

Top Transcription factor binding sites by QIAGEN in the CSNK2B gene promoter:
  • E47
  • Hand1
  • HNF-4alpha1
  • HNF-4alpha2
  • Pax-5
  • PPAR-gamma1
  • PPAR-gamma2

Genomic Locations for CSNK2B Gene

Latest Assembly
chr6:31,665,227-31,670,343
(GRCh38/hg38)
Size:
5,117 bases
Orientation:
Plus strand

Previous Assembly
chr6:31,633,857-31,637,844
(GRCh37/hg19 by Entrez Gene)
Size:
3,988 bases
Orientation:
Plus strand

chr6:31,633,013-31,638,120
(GRCh37/hg19 by Ensembl)
Size:
5,108 bases
Orientation:
Plus strand

Alternative Locations (GRCh38/hg38)

  • chr6(ALT_REF_LOCI_2):3,143,371-3,147,358 (+)
  • chr6(ALT_REF_LOCI_3):2,913,852-2,917,839 (+)
  • chr6(ALT_REF_LOCI_4):2,971,127-2,975,114 (+)
  • chr6(ALT_REF_LOCI_5):3,007,952-3,011,939 (+)
  • chr6(ALT_REF_LOCI_6):2,921,904-2,925,891 (+)
  • chr6(ALT_REF_LOCI_7):2,965,364-2,969,351 (+)

Genomic View for CSNK2B Gene

Genes around CSNK2B on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
CSNK2B Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for CSNK2B Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

Proteins for CSNK2B Gene

  • Protein details for CSNK2B Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    P67870-CSK2B_HUMAN
    Recommended name:
    Casein kinase II subunit beta
    Protein Accession:
    P67870
    Secondary Accessions:
    • B0UXA9
    • P07312
    • P13862
    • Q4VX47

    Protein attributes for CSNK2B Gene

    Size:
    215 amino acids
    Molecular mass:
    24942 Da
    Quaternary structure:
    • Casein kinase II/CK2 is a tetramer composed of an alpha subunit, an alpha' subunit and two beta subunits. The beta subunit dimerization is mediated by zinc ions. Interacts with DYNLT2 (By similarity). Interacts with CD163. Also component of a CK2-SPT16-SSRP1 complex composed of SSRP1, SUPT16H, CSNK2A1, CSNK2A2 and CSNK2B, the complex associating following UV irradiation. Interacts with MUSK; mediates phosphorylation of MUSK by CK2. Interacts with FGF1; this interaction is increased in the presence of FIBP, suggesting a possible cooperative interaction between CSNKB and FIBP in binding to FGF1.

    Three dimensional structures from OCA and Proteopedia for CSNK2B Gene

neXtProt entry for CSNK2B Gene

Post-translational modifications for CSNK2B Gene

  • Phosphorylated by alpha subunit.
  • Ubiquitination at Lys33, Lys100, Lys134, Lys139, Lys191, Lys208, and Lys212
  • Modification sites at PhosphoSitePlus

No data available for DME Specific Peptides for CSNK2B Gene

Domains & Families for CSNK2B Gene

Gene Families for CSNK2B Gene

IUPHAR :
Human Protein Atlas (HPA):
  • Cancer-related genes
  • Plasma proteins
  • Predicted intracellular proteins

Protein Domains for CSNK2B Gene

InterPro:
Blocks:
  • Casein kinase II, regulatory subunit

Suggested Antigen Peptide Sequences for CSNK2B Gene

GenScript: Design optimal peptide antigens:
  • cDNA, FLJ92126, Homo sapiens casein kinase 2, beta polypeptide (CSNK2B), mRNA (B0UXA9_HUMAN)
  • cDNA FLJ50688, highly similar to Casein kinase II subunit beta (B4DUJ4_HUMAN)
  • Protein G5a (CSK2B_HUMAN)

Graphical View of Domain Structure for InterPro Entry

P67870

UniProtKB/Swiss-Prot:

CSK2B_HUMAN :
  • Belongs to the casein kinase 2 subunit beta family.
Family:
  • Belongs to the casein kinase 2 subunit beta family.
genes like me logo Genes that share domains with CSNK2B: view

Function for CSNK2B Gene

Molecular function for CSNK2B Gene

UniProtKB/Swiss-Prot Function:
Regulatory subunit of casein kinase II/CK2. As part of the kinase complex regulates the basal catalytic activity of the alpha subunit a constitutively active serine/threonine-protein kinase that phosphorylates a large number of substrates containing acidic residues C-terminal to the phosphorylated serine or threonine (PubMed:11239457, PubMed:16818610). Participates in Wnt signaling (By similarity).
GENATLAS Biochemistry:
caseine kinase II,beta unit,likely involved in regulation of cell growth

Phenotypes From GWAS Catalog for CSNK2B Gene

Gene Ontology (GO) - Molecular Function for CSNK2B Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0003682 chromatin binding IDA 25519132
GO:0004674 contributes_to protein serine/threonine kinase activity IDA,TAS 1856204
GO:0005102 signaling receptor binding IPI 19233263
GO:0005515 protein binding IPI 10094392
GO:0008134 transcription factor binding IPI 19324893
genes like me logo Genes that share ontologies with CSNK2B: view
genes like me logo Genes that share phenotypes with CSNK2B: view

Human Phenotype Ontology for CSNK2B Gene

HPO Id HPO Name Alternative Ids Definition Synonyms

Animal Models for CSNK2B Gene

MGI Knock Outs for CSNK2B:

Inhibitory RNAs for research

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for CSNK2B

No data available for Enzyme Numbers (IUBMB) , miRNA , Transcription Factor Targets and HOMER Transcription for CSNK2B Gene

Localization for CSNK2B Gene

Subcellular locations from

COMPARTMENTS
Extracellular space Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence
COMPARTMENTS Subcellular localization image for CSNK2B gene
Compartment Confidence
extracellular 5
nucleus 5
cytosol 5
plasma membrane 2
cytoskeleton 2
mitochondrion 1
endoplasmic reticulum 1
endosome 1
lysosome 1
golgi apparatus 1

Gene Ontology (GO) - Cellular Components for CSNK2B Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0000785 chromatin IEA --
GO:0005576 extracellular region TAS --
GO:0005634 nucleus IDA 21282530
GO:0005654 nucleoplasm TAS --
GO:0005737 cytoplasm IBA,IDA 19233263
genes like me logo Genes that share ontologies with CSNK2B: view

No data available for Subcellular locations from UniProtKB/Swiss-Prot and Subcellular locations from the Human Protein Atlas (HPA) for CSNK2B Gene

Pathways & Interactions for CSNK2B Gene

genes like me logo Genes that share pathways with CSNK2B: view

Pathways by source for CSNK2B Gene

1 BioSystems pathway for CSNK2B Gene
4 GeneGo (Thomson Reuters) pathways for CSNK2B Gene
  • Cell adhesion PLAU signaling
  • DNA damage_NHEJ mechanisms of DSBs repair
  • Regulation of CFTR activity (norm and CF)
  • Translation Regulation of EIF2 activity
1 R&D Systems pathway for CSNK2B Gene
1 Tocris pathway for CSNK2B Gene
2 Qiagen pathways for CSNK2B Gene
  • Erythropoietin Pathway
  • NF-KappaB (p50-p65) Pathway
1 GeneTex pathway for CSNK2B Gene

SIGNOR curated interactions for CSNK2B Gene

Activates:
Inactivates:
Is activated by:
Other effect:

Gene Ontology (GO) - Biological Process for CSNK2B Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0006457 protein folding TAS --
GO:0006656 phosphatidylcholine biosynthetic process TAS --
GO:0007165 signal transduction TAS 2513884
GO:0008285 negative regulation of cell proliferation TAS 19324893
GO:0010862 positive regulation of pathway-restricted SMAD protein phosphorylation IDA 19592636
genes like me logo Genes that share ontologies with CSNK2B: view

Drugs & Compounds for CSNK2B Gene

(20) Drugs for CSNK2B Gene - From: DrugBank, ApexBio, HMDB, Tocris, and Novoseek

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
Quercetin Experimental, Investigational Pharma Target Antitumor agent, Non-selective PI 3-kinase inhibitor 68
ATP Investigational Nutra Target 0
Ellagic acid Investigational Pharma Casein kinase 2 (CK2) inhibitor, Selective inhibitor of CK2. Also inhibits glutathione S-transferase 0
CX-4945 (Silmitasertib) Pharma CK2 inhibitor 0
TTP 22 Pharma CK2 inhibitor 0

(9) Additional Compounds for CSNK2B Gene - From: Novoseek, HMDB, and Tocris

Name Synonyms Role CAS Number PubChem IDs PubMed IDs
ADP
  • 5'-Adenylphosphoric acid
  • Adenosine 5'-diphosphate
  • ADENOSINE-5'-diphosphATE
  • H3ADP
  • 5'-Adenylphosphate
58-64-0
TBCA
934358-00-6

(4) Tocris Compounds for CSNK2B Gene

Compound Action Cas Number
Ellagic acid Selective inhibitor of CK2. Also inhibits glutathione S-transferase 476-66-4
TBB Selective cell-permeable CK2 inhibitor 17374-26-4
TBCA Selective CK2 inhibitor 934358-00-6
TMCB Dual-kinase inhibitor; inhibits CK2 and ERK8 905105-89-7

(3) ApexBio Compounds for CSNK2B Gene

Compound Action Cas Number
CX-4945 (Silmitasertib) CK2 inhibitor 1009820-21-6
Ellagic acid Casein kinase 2 (CK2) inhibitor 476-66-4
TTP 22 CK2 inhibitor 329907-28-0
genes like me logo Genes that share compounds with CSNK2B: view

Drug products for research

Transcripts for CSNK2B Gene

mRNA/cDNA for CSNK2B Gene

2 REFSEQ mRNAs :
23 NCBI additional mRNA sequence :
11 Ensembl transcripts including schematic representations, and UCSC links to gene/alias where relevant :

Inhibitory RNAs for research

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for CSNK2B

Alternative Splicing Database (ASD) splice patterns (SP) for CSNK2B Gene

No ASD Table

Relevant External Links for CSNK2B Gene

GeneLoc Exon Structure for
CSNK2B

Expression for CSNK2B Gene

mRNA expression in normal human tissues from GTEx, Illumina, BioGPS, and SAGE for CSNK2B Gene

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, MaxQB, and MOPED for CSNK2B Gene



Protein tissue co-expression partners for CSNK2B Gene

- Elite partner

Transcriptomic regulation report from SPP (The Signaling Pathways Project) for CSNK2B

SOURCE GeneReport for Unigene cluster for CSNK2B Gene:

Hs.73527

Evidence on tissue expression from TISSUES for CSNK2B Gene

  • Liver(4.5)
  • Nervous system(4.5)
  • Blood(2.8)
  • Kidney(2.3)
  • Spleen(2.2)
  • Heart(2.2)
  • Muscle(2.1)
  • Skin(2)
genes like me logo Genes that share expression patterns with CSNK2B: view

Primer products for research

No data available for mRNA expression in embryonic tissues and stem cells from LifeMap Discovery , mRNA differential expression in normal tissues , Protein differential expression in normal tissues , mRNA Expression by UniProt/SwissProt and Phenotype-based relationships between genes and organs from Gene ORGANizer for CSNK2B Gene

Orthologs for CSNK2B Gene

This gene was present in the common ancestor of eukaryotes.

Orthologs for CSNK2B Gene

Organism Taxonomy Gene Similarity Type Details
Chimpanzee
(Pan troglodytes)
Mammalia CSNK2B 29 30
  • 99.84 (n)
OneToOne
Oppossum
(Monodelphis domestica)
Mammalia CSNK2B 30
  • 97 (a)
OneToOne
Dog
(Canis familiaris)
Mammalia CSNK2B 29 30
  • 95.81 (n)
OneToOne
Cow
(Bos Taurus)
Mammalia CSNK2B 29 30
  • 95.04 (n)
OneToOne
Rat
(Rattus norvegicus)
Mammalia Csnk2b 29
  • 94.57 (n)
Mouse
(Mus musculus)
Mammalia Csnk2b 29 16 30
  • 93.8 (n)
OneToOne
Platypus
(Ornithorhynchus anatinus)
Mammalia -- 30
  • 43 (a)
OneToMany
Lizard
(Anolis carolinensis)
Reptilia CSNK2B 30
  • 92 (a)
OneToOne
Tropical Clawed Frog
(Silurana tropicalis)
Amphibia csnk2b 29
  • 81.86 (n)
Str.7978 29
African clawed frog
(Xenopus laevis)
Amphibia Xl.1152 29
Zebrafish
(Danio rerio)
Actinopterygii ck2b 29 30
  • 85.12 (n)
OneToOne
Rainbow Trout
(Oncorhynchus mykiss)
Actinopterygii Omy.293 29
Fruit Fly
(Drosophila melanogaster)
Insecta CkII&bgr; 31
  • 89 (a)
CkIIbeta 29 30
  • 74.88 (n)
OneToMany
CkII&bgr;2 31
  • 65 (a)
Ssl 31
  • 48 (a)
Ste12DOR 31
  • 42 (a)
Worm
(Caenorhabditis elegans)
Secernentea T01G9.6a 31
  • 81 (a)
kin-10 29 30 31
  • 69.83 (n)
OneToMany
A. gosspyii yeast
(Eremothecium gossypii)
Saccharomycetes AGOS_ACR087C 29
  • 55.72 (n)
Baker's yeast
(Saccharomyces cerevisiae)
Saccharomycetes CKB2 29 30 32
  • 52.2 (n)
OneToMany
K. Lactis Yeast
(Kluyveromyces lactis)
Saccharomycetes KLLA0E21869g 29
  • 50.33 (n)
Thale Cress
(Arabidopsis thaliana)
eudicotyledons CKB4 29
  • 56.42 (n)
Alicante grape
(Vitis vinifera)
eudicotyledons Vvi.1389 29
Rice
(Oryza sativa)
Liliopsida Os07g0495100 29
  • 56.6 (n)
Os.11223 29
Corn
(Zea mays)
Liliopsida Zm.808 29
Sea Squirt
(Ciona savignyi)
Ascidiacea CSA.4732 30
  • 88 (a)
OneToMany
Bread mold
(Neurospora crassa)
Ascomycetes NCU02754 29
  • 57.59 (n)
Fission Yeast
(Schizosaccharomyces pombe)
Schizosaccharomycetes ckb1 29
  • 56.87 (n)
Sea Vase
(Ciona intestinalis)
Ascidiacea Cin.7419 29
Species where no ortholog for CSNK2B was found in the sources mined by GeneCards:
  • Actinobacteria (Mycobacterium tuberculosis)
  • African malaria mosquito (Anopheles gambiae)
  • Alpha proteobacteria (Wolbachia pipientis)
  • Amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • Barley (Hordeum vulgare)
  • Beta proteobacteria (Neisseria meningitidis)
  • Chicken (Gallus gallus)
  • Chromalveolata (Phytophthora infestans)
  • Common water flea (Daphnia pulex)
  • E. coli (Escherichia coli)
  • Filamentous fungi (Aspergillus nidulans)
  • Firmicute Bacteria (Streptococcus pneumoniae)
  • Green Algae (Chlamydomonas reinhardtii)
  • Honey Bee (Apis mellifera)
  • Loblloly Pine (Pinus taeda)
  • Malaria Parasite (Plasmodium falciparum)
  • Medicago Trunc (Medicago Truncatula)
  • Moss (Physcomitrella patens)
  • Orangutan (Pongo pygmaeus)
  • Pig (Sus scrofa)
  • Rice Blast Fungus (Magnaporthe grisea)
  • Schistosome Parasite (Schistosoma mansoni)
  • Sea Anemone (Nematostella vectensis)
  • Sea Urchin (Strongylocentrotus purpuratus)
  • Sorghum (Sorghum bicolor)
  • Soybean (Glycine max)
  • Stem Rust Fungus (Puccinia graminis)
  • Sugarcane (Saccharum officinarum)
  • Tomato (Lycopersicon esculentum)
  • Toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • Wheat (Triticum aestivum)

Evolution for CSNK2B Gene

ENSEMBL:
Gene Tree for CSNK2B (if available)
TreeFam:
Gene Tree for CSNK2B (if available)
Aminode:
Evolutionary constrained regions (ECRs) for CSNK2B: view image
Alliance of Genome Resources:
Additional Orthologs for CSNK2B

Paralogs for CSNK2B Gene

(7) SIMAP similar genes for CSNK2B Gene using alignment to 7 proteins:

  • CSK2B_HUMAN
  • N0E466_HUMAN
  • N0E4C7_HUMAN
  • N0E638_HUMAN
  • N0E650_HUMAN
  • N0E6I8_HUMAN
  • Q5SRQ6_HUMAN
genes like me logo Genes that share paralogs with CSNK2B: view

No data available for Paralogs for CSNK2B Gene

Variants for CSNK2B Gene

Sequence variations, with clinical significance, from ClinVar and Humsavar, with links to dbSNP for CSNK2B Gene

SNP ID Clinical significance and condition Chr 06 pos Variation AA Info Type
1030427 Pathogenic: Poirier-Bienvenu neurodevelopmental syndrome 31,669,095(+) A/C
NM_001320.7(CSNK2B):c.292-2A>C
SPLICE_ACCEPTOR
870828 Uncertain Significance: not provided 31,666,899(+) G/T
NM_001320.7(CSNK2B):c.68G>T (p.Cys23Phe)
MISSENSE
870829 Uncertain Significance: not provided 31,669,145(+) T/C
NM_001320.7(CSNK2B):c.340T>C (p.Cys114Arg)
MISSENSE
932465 Likely Pathogenic: not provided 31,666,832(+) A/G
NM_001320.7(CSNK2B):c.1A>G (p.Met1Val)
INITIATIOR_CODON_VARIANT,MISSENSE
973336 Likely Pathogenic: Poirier-Bienvenu neurodevelopmental syndrome 31,669,108(+) C/G
NM_001320.7(CSNK2B):c.303C>G (p.Tyr101Ter)
NONSENSE

dbSNP identifiers (rs#s) for variants without ClinVar clinical significance for CSNK2B Gene

All consequence types are included: molecular consequences (e.g. missense, synonymous), and location-based (e.g. intron, upstream).

Structural Variations from Database of Genomic Variants (DGV) for CSNK2B Gene

Variant ID Type Subtype PubMed ID
dgv10403n54 CNV loss 21841781
dgv10404n54 CNV loss 21841781
nsv1073969 CNV deletion 25765185
nsv1112900 CNV deletion 24896259
nsv1126749 CNV deletion 24896259
nsv1161370 CNV deletion 26073780
nsv830627 CNV loss 17160897

Variation tolerance for CSNK2B Gene

Residual Variation Intolerance Score: 49.2% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 0.58; 12.40% of all genes are more intolerant (likely to be disease-causing)

Additional Variant Information for CSNK2B Gene

Human Gene Mutation Database (HGMD)
CSNK2B
SNPedia medical, phenotypic, and genealogical associations of SNPs for
CSNK2B
Leiden Open Variation Database (LOVD)
CSNK2B

SNP Genotyping and Copy Number Assays for research

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for CSNK2B Gene

Disorders for CSNK2B Gene

MalaCards: The human disease database

(5) MalaCards diseases for CSNK2B Gene - From: OMI, CVR, GTR, ORP, SWI, COP, and GCD