Seroatlas · Human Serome Atlas

CT83

Kita-kyushu lung cancer antigen 1

Also known as: CXorf61, FLJ20611, FLJ22913, KK-LC-1, KKLC1_HUMAN

Cross-references: UniProt · Ensembl · Human Protein Atlas · GeneCards · NCBI Gene

Protein identityUniProt · HPA

UniProt accession
Q5H943
Gene
CT83
Ensembl
ENSG00000204019
Chromosome
X
Canonical length
113 aa
Protein class
Predicted intracellular proteins

OverviewNCBI Gene

Located in nucleus. [provided by Alliance of Genome Resources, Jul 2025]

Canonical amino-acid sequenceUniProt

113 residues, UniProt reviewed canonical sequence.

>Q5H943|CT83
     1  MNFYLLLASS ILCALIVFWK YRRFQRNTGE MSSNSTALAL VRPSSSGLIN SNTDNNLAVY
    61  DLSRDILNNF PHSIARQKRI LVNLSMVENK LVELEHTLLS KGFRGASPHR KST

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CT83 can act on the native protein depends on physical access: surface and secreted proteins are reachable by circulating antibodies, intracellular proteins usually are not.

Antibody reachability
Cell surface
Secreted
No
Transmembrane segments
1
Mean surface accessibility (rSASA)
0.57
Highest tissue expression
66 nTPM

Expression across tissuesHPA

Tissue

  • testis: 66 nTPM
  • salivary gland: 2.6 nTPM
  • stomach: 0.2 nTPM
  • breast: 0.1 nTPM
  • adipose tissue: 0 nTPM
  • adrenal gland: 0 nTPM

Single-cell type

  • late spermatids: 4,894 nCPM
  • early spermatids: 852 nCPM
  • late primary spermatocytes: 303 nCPM
  • gastric progenitor cells: 18 nCPM
  • leydig cells: 4 nCPM
  • breast lactating cells: 2.4 nCPM

Immune cell

  • basophil: 0 nTPM
  • classical monocyte: 0 nTPM
  • eosinophil: 0 nTPM
  • gdT-cell: 0 nTPM
  • intermediate monocyte: 0 nTPM
  • MAIT T-cell: 0 nTPM

Brain region

  • amygdala: 0 nTPM
  • basal ganglia: 0 nTPM
  • cerebellum: 0 nTPM
  • cerebral cortex: 0 nTPM
  • choroid plexus: 0 nTPM
  • hippocampal formation: 0 nTPM

DiseaseUniProt · ClinVar · IEDB · PubMed

Four sources answering four different questions about CT83.

Disease | ImmuneIEDB

Conditions an epitope on CT83 was assayed in.

Genetic constraint and essentialitygnomAD · DepMap

Does the body need this protein intact? Low LOEUF or a strong DepMap dependency means loss or blockade of the protein is likely to be felt.

gnomAD LOEUF (loss-of-function intolerance)
1.91
gnomAD pLI
0.08
gnomAD missense Z
-0.01
DepMap mean gene effect
0.04
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 3% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Cellular components

Protein domainsUniProt · Pfam · InterPro

  • Kita-kyushu lung cancer antigen 1
  • Kita-kyushu lung cancer antigen 1

KeywordsUniProt

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CT83 as an antibody target. Whether an autoantibody or antibody against CT83 could matter depends on whether native CT83 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CT83 is annotated at the cell surface, where native CT83 is exposed to circulating antibodies and is a prime autoantibody target that could block, deplete, or overstimulate it.

Annotation status

The present source text does not explicitly label CT83 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CT83. Study-independent annotations aggregated from UniProt, Human Protein Atlas, PubMed, IEDB, Pfam, InterPro, Gene Ontology, AlphaFold, gnomAD, DepMap, ClinVar, TCGA. Catalog release seroatlas-reviewed-human-uniprot-20260313.

Seroatlas is the reference for exploring autoantibody and antibody serology at the human-protein level: the autoreactome and human serome, multiplex serology (HuProt, HuScan, VirScan, PhIP-Seq).

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