KLRK1 and plasma cell myeloma: Elotuzumab enhanced NK cytotoxicity to myeloma cells in an independent CD16 expression manner when the expression level of NKG2D was high on NK cells.54 On the contrary, daratumumab decreases the number of NK cells in patients with RRMM.55 Daratumumab decreased CD38+ NK cells significantly, which are present in the majority of the population, accounting for approximately 85%, although daratumumab did not decrease CD38‐/low NK cells.56 However, CD38‐/low NK cells play an important role in ADCC compared with CD38+ NK cells.