NFKB1 and Miyoshi myopathy: The Ibrutinib cytotoxicity in MM occurs via inhibition of NF-κB pathway; in fact, Ibrutinib stops the Ser536 phosphorylation of the p65 subunit of NF-κB, blocking its nuclear translocation, thus resulting in down-regulation of anti-apoptotic proteins such as Bcl-xL, FLIP(L) and survivin and activating caspase-mediated apoptosis in malignant PCs [17].