CD19 and ovarian cancer: The results showed that both CLDN6-CAR1 and -CAR2 NK cells exhibited stronger cytotoxicity than CD19-CAR NK or parental NK-92MI cells after coculture with all 4 ovarian cancer cell lines at the indicated effector-to-target (E:T) ratios but not CLDN6-negative PC-3 GL cells (Fig. 2B).