CHEK2 and breast cancer: We limited the analysis of germline testing to breast cancer–associated genes in which PVs were detected frequently enough to provide sufficient cases for analysis (n ≥ 20): ATM, BRCA1/2, CHEK2, and PALB2. We included the Lynch syndrome (LS)–associated genes as a single category (MLH1, MSH2, MSH6, and PMS2), because they are commonly tested on multiple-gene panels, but their breast cancer association is uncertain (1,3).