This gene is associated with an increased risk for autosomal dominant adult-onset cancers including breast, colon, thyroid, and prostate cancers, and possibly others.33–37 These cancer risks, particularly the risks for breast cancer, depend on the variant and family history.34,38 Several studies have found that pathogenic variants in CHEK2 are observed at a frequency higher than those of variants identified in other breast cancer-associated genes on multi-gene panels,22,26,39 which is consistent with our observations. This evidence concerns the gene CHEK2 and breast cancer.