CD38 and plasma cell myeloma: CD38-expressing malignant B cells and long-lived PCs can be targeted by novel B cell–targeted therapies such as the anti-CD38 mAbs daratumumab (DARA, trade name Darzalex) or isatuximab (trade name Sarclisa), which are currently approved for treatment of multiple myeloma (MM) (7, 8, 9, 10).