The PARP inhibitors tested were: R503, an experimental compound developed by the company Radikal Therapeutics; ABT-888 (Veliparib), a PARP inhibitor currently being used in several phase III clinical trials (NCT02264990, NCT02163694, NCT02152982); and olaparib (LynparzaTM), a drug approved in 2014 for the treatment of ovarian cancer positive for BRCA1/2 mutations. The gene discussed is PARP1; the disease is ovarian cancer.