CD38 and plasma cell myeloma: MM therapy has significantly advanced in the last 20 years, including the introduction of PIs, such as bortezomib, ixazomib, and carfilzomib; immunomodulatory agents (IMIDs), like lenalidomide and pomalidomide; monoclonal antibodies targeting myeloma cell surface antigens (CD38: daratumumab and isatuximab; SLAMF7: elotuzumab); and autologous hematopoietic stem cell transplantation [41, 42].