CD38 and neoplasm: Daratumumab participates in immune-mediated antibody-dependent cytotoxicity, antibody-dependent cellular phagocytosis and component-dependent cytotoxicity through Fc-dependent immune effector mechanisms, thereby reducing the number of CD38-positive immunosuppressive cells, including T regulatory cells (Tregs), natural killer (NK) cells, regulatory B cells, and myeloid-derived suppressor cells, affecting CD38 nonmyeloid tumor cells that mediate GVHD and theoretically affects GVHD episodes [61,62].