MCL1 and Miyoshi myopathy: Importantly, APRIL binding to BCMA triggers multiple signaling pathways to further promote drug resistance of MM cells and the progression of immunosuppressive BM milieu via induction of the key downstream anti-apoptotic genes (Mcl-1, Bcl-2/Bcl-xL) and immune regulatory genes (IL-10, PD-L1, VEGF, TGF-β) in MM cells [18,19].