CHEK2 and cancer: Defects in DNA damage response (DDR) genes including breast cancer type 1/2 susceptibility gene (BRCA1/2), ataxia-telangiectasia mutated (ATM), checkpoint kinase 2 (CHEK2), and partner and localiser of BRCA2 (PLAB2) are common in advanced disease, occurring in approximately 12% of metastatic PCa cases, and may upregulate PSMA expression via replication stress and metabolic demand [55,56].