Finally, a relevant consequence of MM cells-BM stromal cells adhesion is the IL-6 mediated up-regulation of PD-L1 (CD274 or B7-H1) expression on MM cells, that increases their proliferative ability, induces resistance to dexamethasone and melphalan, and down-regulates anti-tumor immune T cell responses [61]. Here, CD274 is linked to Miyoshi myopathy.