IF staining showed that knockdown of SOX9 resulted in a reduction in RAD51 foci accumulation and a concomitant increase in γH2AX foci accumulation when compared with the control group following olaparib treatment, indicative of aggravated DNA damage and defective DNA repair capability in the SOX9 deficient setting of ovarian cancer cells. The gene discussed is RAD51; the disease is ovarian cancer.