Interestingly, in BRCA1-deficient ovarian cancer models, PARP inhibition with olaparib increased CD4+ and CD8+ T cells in the tumor and in circulation, reduced their expression of inhibitory receptors PD-1, Tim-3, and Lag-3, and increased their levels of TNF-alpha and IFN-γ secretion. Here, PARP1 is linked to ovarian cancer.