# CASR

Source: https://onco.cc/targets/casr/  
OnCo record `casr` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CASR (Extracellular calcium-sensing receptor) is a gene. The public catalogues list it as a drug target, and an approved or late-stage drug is recorded against it.

## Summary

G protein-coupled receptor that senses changes in the extracellular concentration of calcium ions and plays a key role in maintaining calcium homeostasis. Senses fluctuations in the circulating calcium concentration: activated by elevated circulating calcium, leading to decreased parathyroid hormone (PTH) secretion in parathyroid glands. In kidneys, acts as a key regulator of renal tubular calcium resorption.

Open Targets scores its association with cancer at 0.61 (direct and indirect evidence; datatypes clinical 0.91, literature 0.98, genetic association 0.00, somatic mutation 0.23, animal model 0.59).

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: calcium sensing receptor; Extracellular calcium-sensing receptor; NSHPT; GPRC2A; HHC1
- Tags: cancer-genes-wave
- Symbol: CASR
- Class: other
- Biology: G protein-coupled receptor that senses changes in the extracellular concentration of calcium ions and plays a key role in maintaining calcium homeostasis. Senses fluctuations in the circulating calcium concentration: activated by elevated circulating calcium, leading to decreased parathyroid hormone (PTH) secretion in parathyroid glands. In kidneys, acts as a key regulator of renal tubular calcium resorption. Ligand binding causes a conformation change that triggers signalling via guanine nucleotide-binding proteins (G proteins) and modulates the activity of downstream effectors. CASR is coupled with different G(q)/G(11), G(i)/G(o)- or G(s)-classes of G proteins depending on the context. In the parathyroid and kidney, CASR signals through G(q)/G(11) and G(i)/G(o) G proteins: G(q)/G(11) coupling activates phospholipase C-beta, releasing diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) second messengers, while G(i)/G(o) coupling mediates inhibition of adenylate cyclase activity. Location: Cell membrane (UniProt). Locus 3q13.33-q21.1 (HGNC).

## Notes

- Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: Open Targets known-drug datatype score 0.91. Evidence tier "approved-drug" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:1514: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:1514
- UniProt P41180: https://www.uniprot.org/uniprotkb/P41180/entry
- NCBI Gene 846: https://www.ncbi.nlm.nih.gov/gene/846
- Ensembl ENSG00000036828: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000036828

## Connected records

- collections: [Open Targets Platform](https://onco.cc/collections/open-targets/)

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JSON: https://onco.cc/api/v1/entities/casr.json