CASR and breast cancer: CaSR belongs to class C of the GPCR, which signals in response to Ca2+ and other ligands, such as gadolinium, polypeptides, and certain antibiotics.21 CaSR can promote the development of bone metastasis in both renal cell carcinoma22 and breast cancer.23 Based on the KEGG Enrichment analysis, a total of 21 signaling pathways are involved in the T1‐T2 DEGs, of which the maturity onset diabetes of the young may be of most interest.