Current testing panels mostly feature genes involved in DNA repair and cell cycle control, such as BRCA1 and BRCA2, which explain the majority of inherited ovarian and breast cancer, as well as 22 other genes including TP53, PTEN, CDH1, ATM, CHEK2, PALB2, and mismatch repair genes, MSH1, MSH2. Here, CHEK2 is linked to breast cancer.