Daratumumab is a human IgG1k mAb that targets CD38, a cell surface protein that is highly expressed on myeloma cells and is involved in tumorigenesis, and promotes multiple myeloma cell cytotoxicity [15–17], phagocytosis [17, 18], induces apoptosis [17, 19], and depletes CD38-positive immune regulatory T, B, and myeloid-derived suppressor cells [20]. This evidence concerns the gene CD38 and plasma cell myeloma.