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Aliases for CLDN18 Gene

Aliases for CLDN18 Gene

  • Claudin 18 2 3 5
  • Surfactant Associated Protein J 2 3
  • Surfactant, Pulmonary Associated Protein J 3
  • Surfactant Associated 5 3
  • SFTA5 3
  • SFTPJ 3

External Ids for CLDN18 Gene

Previous HGNC Symbols for CLDN18 Gene


Previous GeneCards Identifiers for CLDN18 Gene

  • GC03P134713
  • GC03P138520
  • GC03P138999
  • GC03P139049
  • GC03P139038
  • GC03P139200
  • GC03P137717
  • GC03P135092

Summaries for CLDN18 Gene

Entrez Gene Summary for CLDN18 Gene

  • This gene encodes a member of the claudin family. Claudins are integral membrane proteins and components of tight junction strands. Tight junction strands serve as a physical barrier to prevent solutes and water from passing freely through the paracellular space between epithelial or endothelial cell sheets, and also play critical roles in maintaining cell polarity and signal transductions. This gene is upregulated in patients with ulcerative colitis and highly overexpressed in infiltrating ductal adenocarcinomas. PKC/MAPK/AP-1 (protein kinase C/mitogen-activated protein kinase/activator protein-1) dependent pathway regulates the expression of this gene in gastric cells. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Jun 2010]

GeneCards Summary for CLDN18 Gene

CLDN18 (Claudin 18) is a Protein Coding gene. Diseases associated with CLDN18 include Ulcerative Colitis and Mucinous Ovarian Cystadenoma. Among its related pathways are Cell junction organization and Tight junction. GO annotations related to this gene include identical protein binding and structural molecule activity. An important paralog of this gene is CLDN15.

UniProtKB/Swiss-Prot for CLDN18 Gene

  • Plays a major role in tight junction-specific obliteration of the intercellular space, through calcium-independent cell-adhesion activity.

Gene Wiki entry for CLDN18 Gene

No data available for Tocris Summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for CLDN18 Gene

Genomics for CLDN18 Gene

Regulatory Elements for CLDN18 Gene

Enhancers for CLDN18 Gene
GeneHancer Identifier Score Enhancer Sources TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor Binding Sites within enhancer Other Gene Targets for Enhancer

Enhancers around CLDN18 on UCSC Golden Path with GeneCards custom track

Genomic Location for CLDN18 Gene

137,998,735 bp from pter
138,033,655 bp from pter
34,921 bases
Plus strand

Genomic View for CLDN18 Gene

Genes around CLDN18 on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
CLDN18 Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for CLDN18 Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for CLDN18 Gene

Proteins for CLDN18 Gene

  • Protein details for CLDN18 Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Protein Accession:
    Secondary Accessions:
    • A5PL21
    • Q96PH4

    Protein attributes for CLDN18 Gene

    261 amino acids
    Molecular mass:
    27856 Da
    Quaternary structure:
    No Data Available

    Alternative splice isoforms for CLDN18 Gene


neXtProt entry for CLDN18 Gene

Proteomics data for CLDN18 Gene at MOPED

Post-translational modifications for CLDN18 Gene

  • Modification sites at PhosphoSitePlus
  • Modification sites at neXtProt

Other Protein References for CLDN18 Gene

Antibody Products

No data available for DME Specific Peptides for CLDN18 Gene

Domains & Families for CLDN18 Gene

Gene Families for CLDN18 Gene

Protein Domains for CLDN18 Gene

Suggested Antigen Peptide Sequences for CLDN18 Gene

GenScript: Design optimal peptide antigens:

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the claudin family.
  • Belongs to the claudin family.
genes like me logo Genes that share domains with CLDN18: view

Function for CLDN18 Gene

Molecular function for CLDN18 Gene

UniProtKB/Swiss-Prot Function:
Plays a major role in tight junction-specific obliteration of the intercellular space, through calcium-independent cell-adhesion activity.
genes like me logo Genes that share phenotypes with CLDN18: view

Animal Models for CLDN18 Gene

MGI Knock Outs for CLDN18:

Animal Model Products

  • Taconic Biosciences Mouse Models for CLDN18

miRNA for CLDN18 Gene

miRTarBase miRNAs that target CLDN18

No data available for Enzyme Numbers (IUBMB) , Gene Ontology (GO) - Molecular Function , Human Phenotype Ontology , Transcription Factor Targets and HOMER Transcription for CLDN18 Gene

Localization for CLDN18 Gene

Subcellular locations from UniProtKB/Swiss-Prot for CLDN18 Gene

Cell junction, tight junction. Cell membrane; Multi-pass membrane protein.

Subcellular locations from

Jensen Localization Image for CLDN18 Gene COMPARTMENTS Subcellular localization image for CLDN18 gene
Compartment Confidence
plasma membrane 5
endoplasmic reticulum 1

No data available for Gene Ontology (GO) - Cellular Components for CLDN18 Gene

Pathways & Interactions for CLDN18 Gene

genes like me logo Genes that share pathways with CLDN18: view

Interacting Proteins for CLDN18 Gene

Gene Ontology (GO) - Biological Process for CLDN18 Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0034329 cell junction assembly TAS --
GO:0048565 digestive tract development IEA --
GO:0070830 bicellular tight junction assembly TAS --
GO:0071847 TNFSF11-mediated signaling pathway IEA --
genes like me logo Genes that share ontologies with CLDN18: view

No data available for SIGNOR curated interactions for CLDN18 Gene

Drugs & Compounds for CLDN18 Gene

(1) Drugs for CLDN18 Gene - From: HMDB

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
calcium Nutra 0
genes like me logo Genes that share compounds with CLDN18: view

Transcripts for CLDN18 Gene

Unigene Clusters for CLDN18 Gene

Claudin 18:
Representative Sequences:

Alternative Splicing Database (ASD) splice patterns (SP) for CLDN18 Gene

ExUns: 1 ^ 2a · 2b ^ 3 ^ 4 ^ 5 ^ 6a · 6b
SP2: - -
SP3: -

Relevant External Links for CLDN18 Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for CLDN18 Gene

mRNA expression in normal human tissues for CLDN18 Gene

mRNA differential expression in normal tissues according to GTEx for CLDN18 Gene

This gene is overexpressed in Stomach (x39.9) and Lung (x10.9).

Protein differential expression in normal tissues from HIPED for CLDN18 Gene

This gene is overexpressed in Stomach (40.0), Lung (19.5), and Cardia (6.4).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, PaxDb, and MOPED for CLDN18 Gene

SOURCE GeneReport for Unigene cluster for CLDN18 Gene Hs.655324

mRNA Expression by UniProt/SwissProt for CLDN18 Gene

Tissue specificity: Concentrated at the cell-cell borders of epithelial cells.
genes like me logo Genes that share expression patterns with CLDN18: view

Protein tissue co-expression partners for CLDN18 Gene

Primer Products

Orthologs for CLDN18 Gene

This gene was present in the common ancestor of chordates.

Orthologs for CLDN18 Gene

Organism Taxonomy Gene Similarity Type Details
(Bos Taurus)
Mammalia CLDN18 35
  • 84.93 (n)
  • 83.52 (a)
CLDN18 36
  • 89 (a)
(Canis familiaris)
Mammalia CLDN18 35
  • 92.85 (n)
  • 94.64 (a)
CLDN18 36
  • 94 (a)
(Mus musculus)
Mammalia Cldn18 35
  • 87.87 (n)
  • 90.42 (a)
Cldn18 16
Cldn18 36
  • 88 (a)
(Pan troglodytes)
Mammalia CLDN18 35
  • 99.49 (n)
  • 99.62 (a)
CLDN18 36
  • 100 (a)
(Rattus norvegicus)
Mammalia Cldn18 35
  • 82.12 (n)
  • 83.52 (a)
(Monodelphis domestica)
Mammalia CLDN18 36
  • 85 (a)
(Gallus gallus)
Aves CLDN18 35
  • 74.19 (n)
  • 76.26 (a)
CLDN18 36
  • 75 (a)
(Anolis carolinensis)
Reptilia CLDN18 36
  • 75 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia cldn18 35
  • 71.15 (n)
  • 77.08 (a)
African clawed frog
(Xenopus laevis)
Amphibia MGC68719 35
(Danio rerio)
Actinopterygii cldn18 35
  • 52.18 (n)
  • 37.38 (a)
CLDN18 36
  • 32 (a)
sea squirt
(Ciona savignyi)
Ascidiacea -- 36
  • 25 (a)
CSA.10090 36
  • 30 (a)
Species with no ortholog for CLDN18:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • African malaria mosquito (Anopheles gambiae)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • baker's yeast (Saccharomyces cerevisiae)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • fruit fly (Drosophila melanogaster)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • platypus (Ornithorhynchus anatinus)
  • rainbow trout (Oncorhynchus mykiss)
  • rice (Oryza sativa)
  • 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)
  • thale cress (Arabidopsis thaliana)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)
  • worm (Caenorhabditis elegans)

Evolution for CLDN18 Gene

Gene Tree for CLDN18 (if available)
Gene Tree for CLDN18 (if available)

Paralogs for CLDN18 Gene

Paralogs for CLDN18 Gene

(18) SIMAP similar genes for CLDN18 Gene using alignment to 2 proteins:

genes like me logo Genes that share paralogs with CLDN18: view

Variants for CLDN18 Gene

Sequence variations from dbSNP and Humsavar for CLDN18 Gene

SNP ID Clin Chr 03 pos Sequence Context AA Info Type
VAR_033775 -
rs329136 -- 138,033,801(-) GGAAC(A/G)ACACC downstream-variant-500B
rs2289767 -- 138,010,142(-) GAGGG(A/G)AGCTC intron-variant, upstream-variant-2KB
rs1141890 -- 138,032,282(+) CAGCC(A/G)GTCAT utr-variant-3-prime
rs891349 -- 138,014,829(+) ACTTA(A/G)ATAAG intron-variant

Structural Variations from Database of Genomic Variants (DGV) for CLDN18 Gene

Variant ID Type Subtype PubMed ID
nsv428422 CNV Gain+Loss 18775914
nsv877535 CNV Gain 21882294
dgv1511e1 CNV Complex 17122850
nsv460863 CNV Loss 19166990
esv2751978 CNV Loss 17911159
nsv528340 CNV Gain 19592680
dgv1512e1 CNV Complex 17122850

Variation tolerance for CLDN18 Gene

Residual Variation Intolerance Score: 29.8% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 4.99; 68.28% of all genes are more intolerant (likely to be disease-causing)

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot and Relevant External Links for CLDN18 Gene

Disorders for CLDN18 Gene

MalaCards: The human disease database

(2) MalaCards diseases for CLDN18 Gene - From: DISEASES and GeneCards

Disorder Aliases PubMed IDs
ulcerative colitis
  • left-sided ulcerative colitis
mucinous ovarian cystadenoma
  • mucinous cystadenoma of ovary
- elite association - COSMIC cancer census association via MalaCards

Relevant External Links for CLDN18

Atlas of Genetics and Cytogenetics in Oncology and Haematology:
genes like me logo Genes that share disorders with CLDN18: view

No data available for UniProtKB/Swiss-Prot and Genatlas for CLDN18 Gene

Publications for CLDN18 Gene

  1. Claudin-18, a novel downstream target gene for the T/EBP/NKX2.1 homeodomain transcription factor, encodes lung- and stomach-specific isoforms through alternative splicing. (PMID: 11585919) Niimi T. … Kimura S. (Mol. Cell. Biol. 2001) 3 4 23 67
  2. Transcriptional activation of the human claudin-18 gene promoter through two AP-1 motifs in PMA-stimulated MKN45 gastric cancer cells. (PMID: 18032479) Yano K. … Niimi T. (Am. J. Physiol. Gastrointest. Liver Physiol. 2008) 3 23
  3. New markers of pancreatic cancer identified through differential gene expression analyses: claudin 18 and annexin A8. (PMID: 18223320) Karanjawala Z.E. … Hruban R.H. (Am. J. Surg. Pathol. 2008) 3 23
  4. Immunohistochemical staining of Reg IV and claudin-18 is useful in the diagnosis of gastrointestinal signet ring cell carcinoma. (PMID: 18580680) Sentani K. … Yasui W. (Am. J. Surg. Pathol. 2008) 3 23
  5. Increased expression of the tight junction molecule claudin-18 A1 in both experimental colitis and ulcerative colitis. (PMID: 18831034) Zwiers A. … Bouma G. (Inflamm. Bowel Dis. 2008) 3 23

Products for CLDN18 Gene

Sources for CLDN18 Gene