CD38 and Miyoshi myopathy: Treatment for multiple myeloma (MM) has improved over the last few decades [1,2] with the introduction of new treatments and strategies, including proteasome inhibitors (PIs) (e.g., bortezomib, carfilzomib and ixazomib) [3,4,5,6], immunomodulatory therapies (IMiDs) (e.g., lenalidomide and pomalidomide) [7,8,9,10], and anti-CD38 monoclonal antibodies (mAbs) (e.g., daratumumab and isatuximab) [11,12,13,14], as well as combinations of these in doublet, triplet, or quadruplet regimens.