Seroatlas · Human Serome Atlas

CCL21

C-C motif chemokine 21

Also known as: 6Ckine, CCL21_HUMAN, CKb9, ECL, exodus-2, SCYA21, SLC, TCA4

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

Protein identityUniProt · HPA

UniProt accession
O00585
Gene
CCL21
Ensembl
ENSG00000137077
Chromosome
9
Canonical length
134 aa
Protein class
Cancer-related genes, Plasma proteins, Predicted secreted proteins
Secretome location
Secreted to blood

OverviewNCBI Gene

This antimicrobial gene is one of several CC cytokine genes clustered on the p-arm of chromosome 9. Cytokines are a family of secreted proteins involved in immunoregulatory and inflammatory processes. The CC cytokines are proteins characterized by two adjacent cysteines. Similar to other chemokines the protein encoded by this gene inhibits hemopoiesis and stimulates chemotaxis. This protein is chemotactic in vitro for thymocytes and activated T cells, but not for B cells, macrophages, or neutrophils. The cytokine encoded by this gene may also play a role in mediating homing of lymphocytes to secondary lymphoid organs. It is a high affinity functional ligand for chemokine receptor 7 that is expressed on T and B lymphocytes and a known receptor for another member of the cytokine family (small inducible cytokine A19). [provided by RefSeq, Sep 2014]

Canonical amino-acid sequenceUniProt

134 residues, UniProt reviewed canonical sequence.

>O00585|CCL21
     1  MAQSLALSLL ILVLAFGIPR TQGSDGGAQD CCLKYSQRKI PAKVVRSYRK QEPSLGCSIP
    61  AILFLPRKRS QAELCADPKE LWVQQLMQHL DKTPSPQKPA QGCRKDRGAS KTGKKGKGSK
   121  GCKRTERSQT PKGP

LocalizationUniProt · AlphaFold · HPA

Whether an antibody against CCL21 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
Secreted
Secreted
Yes
Transmembrane segments
0
Mean surface accessibility (rSASA)
0.53
Highest tissue expression
2,551 nTPM

Expression across tissuesHPA

Tissue

  • lymph node: 2,551 nTPM
  • tonsil: 937 nTPM
  • thyroid gland: 498 nTPM
  • small intestine: 471 nTPM
  • spleen: 317 nTPM
  • appendix: 254 nTPM

Single-cell type

  • lymphatic endothelial cells: 6,469 nCPM
  • hepatic stellate cells: 149 nCPM
  • pericytes: 92 nCPM
  • schwann cells: 31 nCPM
  • melanocytes: 14 nCPM
  • late spermatids: 9.9 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

  • choroid plexus: 2.5 nTPM
  • medulla oblongata: 2.1 nTPM
  • cerebral cortex: 1.7 nTPM
  • pons: 1.6 nTPM
  • hypothalamus: 1.4 nTPM
  • white matter: 1.4 nTPM

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)
1.21
gnomAD pLI
0.04
gnomAD missense Z
0.12
DepMap mean gene effect
0.08
DepMap dependency class
selective

Cancer expressionTCGA

Across TCGA tumor cohorts, this protein is over-expressed in roughly 2% of surveyed tumor types (aggregate summary; per-cohort expression, alteration, and survival load in the interactive view).

OntologyGO

Biological processes

Molecular functions

Cellular components

Protein domainsUniProt · Pfam · InterPro

KeywordsUniProt

InteractionsUniProt · HPA

Protein binding partners of CCL21 in the human serome: UniProt-annotated complex subunits plus reported interactors. Each links to its own Seroatlas record.

Antibody and autoantibody relevanceSeroatlas analysis

Seroatlas reads CCL21 as an antibody target. Whether an autoantibody or antibody against CCL21 could matter depends on whether native CCL21 is physically reachable, whether the body needs it intact, and whether it acts in a disease-relevant tissue.

CCL21 is annotated as secreted, so native CCL21 circulates and is directly accessible to antibodies. Secreted and cell-surface proteins are the autoantibody targets most likely to act like drugs, blocking or depleting the native protein.

Annotation status

The present source text does not explicitly label CCL21 as an autoantigen. Seroatlas presents hypothesis context only and does not manufacture a known-serology claim.

Canonical record: https://seroatlas.com/gene/CCL21. 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).

© 2026 · Seroatlas, Discover Oregon LLC · Terms of use

Loading the interactive Seroatlas protein explorer...