XCR1 and breast carcinoma: The expression of XCR1 is inhibited in human breast cancer cells in vitro and in vivo through inhibiting the mitogen‐activated protein kinase (MAPK) and phosphatidylinositol‐4,5‐bisphosphate 3‐kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway (Wang et al., 2015).