PARP1 and Familial prostate cancer: A recent study shows that Trop2 induces neuroendocrine phenotype of prostate cancer, and overexpression of Trop2 leads to the significant increase in Poly(ADP-Ribose) polymerase 1 (PARP1) [84], an enzyme critical for DNA repair regulation, replication, transcription, and chromatin remodeling [149].