CHEK2 and prostate cancer: Rare variants in several genes that were initially implicated in risk for breast or ovarian cancer predisposition (e.g., BRCA1 [5], BRCA2 [6,7], CHEK2 [8], BRIP1 [5], and ATM [9]), as well as the mismatch repair (MMR) genes [10], have also been reported to increase the risk of prostate cancer.