Despite its identification as a PARP inhibitor sensitizer in multiple settings, ATM loss in PCa does not appear to consistently confer a strong benefit to PARP inhibitor-treated patients, in contrast to the loss of BRCA2 that was consistently associated with the highest benefit to patients treated with multiple PARP inhibitors [98,108,109,110,111,112,113,114]. This evidence concerns the gene ATM and posterior cortical atrophy.