To further confirm this finding, we generated OVCAR4 cells expressing a doxycycline-inducible BRCA2 shRNA (Fig. S1A).19 Treating OVCAR4 cells depleted of BRCA2 with CX-5461 led to a two-fold reduction in cell proliferation (Fig. S1B), which is consistent with the magnitude of reduction previously reported in the PEO1 ovarian cancer cell line harbouring BRCA2 knockout.26 Together, these data indicate that inducing HR deficiency in HR-proficient cells can enhance their sensitivity to CX-5461. This evidence concerns the gene BRCA2 and ovarian cancer.