As various other genes associated with BRCA1/2 have been indicated to contribute to homologous recombination and DNA repair (such as ATM Serine/Threonine Kinase [ATM], BRCA1 Interacting Helicase I [BRIP1], Checkpoint Kinase 2 [CHEK2], RAD51 Paralog C [RAD51C] and Partner And Localizer of BRCA2 [PALB2]), the search for actionable variants responsible for hereditary BC and/or OVC needs to be expanded. This evidence concerns the gene ATM and breast cancer.