S1PR2 and plasma cell myeloma: TCA-induced increased expression of S1PR2 and cancer cell migration have been detected in cholangiocarcinoma or esophageal adenocarcinoma [10, 41], while, S1PR2-mediated signaling are reported to be associated with anti-cancer signaling in various cancers, including hepatocellular carcinoma, breast cancer or myeloma [42–45] and some hormones and anti-cancer agents were found to activate the expression of S1PR2 [42].