CHEK2 and breast cancer: Moreover, there are some other genes, such as PALB2, BRIP1, ATM, CHEK2, BARD1, RAD51C, RAD51D, NBN, NF1, and MMR genes that are classified as moderate or low penetrance genes for the risk of BC/OC (Table 1), but the increasing evidence of associated cancer risks and the availability of recommendations for the management of the variant carriers suggest that they should be included, whenever possible, in a gene panel for BC/OC predisposition.