CHEK2 and breast carcinoma: Published risk estimates for colorectal cancer from CHEK2 PTV are more modest (OR ~2) and conflicting than those for female breast cancer and prostate cancer; higher estimates of risk are driven by studies of multiplex families.17 Published risk for colorectal cancer from CHEK2 PMV tend to be even lower (OR<2) or non-significant.2,18 Given this, a recent ACMG review and clinical practice guideline on management2 concluded that CHEK2 heterozygosity is not clinically actionable for colorectal cancer risk in isolation and to offer surveillance as per family history.