CD33 and neoplasm: To measure these parameters, E:T titration experiments were performed using two variants of K562 as the target cells: (i) CD33(+)CD16b(-) cells that overexpress CD33, intended to represent tumor cells; and (ii) CD33(+)CD16b(+) cells that overexpress both CD33 and CD16b, intended to model normal myeloid cells in this experiment (Figure 2F).