CD38 and infection: Risk for severe infections in MM is caused by secondary immunodeficiency [3, 4] and potentiated by novel treatments, including monoclonal antibodies (mAb; i.e. anti-CD38 [daratumumab, isatuximab] or anti-SLAMF7 [elotuzumab]), immunomodulatory agents (IMiDs; i.e. thalidomide, lenalidomide), proteasome inhibitors (PI; i.e. bortezomib, carfilzomib), and accompanying steroids [8–10].