CD38 is a transmembrane glycoprotein type II, which is expressed on normal hematopoietic cells and in non-hematopoietic tissues. Notably, CD38 is highly expressed in multiple myeloma, chronic lymphocytic leukemia, and other diseases. CD38 plays several roles, including ectoenzyme, receptor, adhesion molecule, and is involved in signal transduction. The cytotoxic mechanisms of daratumumab, which is considered a new high affinity human therapeutic mAb against a single CD38 epitope. CD38 represents a promising target for mAb-based immunotherapy, which has already and will continue to transform the treatment landscape into diseases, including multiple myeloma.