Components of individual risk assessment are based on integral biomarkers: Breast Cancer Surveillance Consortium 5-year risk; genomic tests for rare high/moderate-penetrance mutations in a number of genes, including the following: BRCA1, BRCA2, ATM, CDH1, CHEK2, PALB2, PTEN, STK11 and TP53; and polygenic risk score from 96 lower-risk common genetic variants (SNPs) with known association to breast cancer, updated as data emerge. This evidence concerns the gene CHEK2 and breast cancer.