FCGR3A and neoplasm: Human NK cells can be broadly classified into two subsets based on CD56 and CD16 surface marker expression: CD56brightCD16dim/low, these cells are less cytotoxic but secrete pro-inflammatory cytokines upon stimulation (7, 11) CD56dimCD16high; this highly cytotoxic subset dominates the peripheral blood and plays a major role in NK-mediated tumor cell killing (7, 11).