TNFSF13B and Miyoshi myopathy: APRIL and BAFF, via binding to BCMA and TACI, further activate NFκB pathways and upregulate antiapoptotic proteins (Mcl-1, Bcl-2, Bcl-xL) to protect MM cells against dexamethasone- and serum deprivation-induced cell death (31, 58, 59) (Figure 1).