PALB2 and breast cancer: Moreover, based on the sequencing genomic DNA (from 1,370 cases and 1,635 controls), approximately 5.6% of patients are the carriers of a pathogenic variant in breast cancer gene 1 (BRCA1), BRCA2, partner and localizer of BRCA2 (PALB2), or tumor protein 53 which are the main penetrant genes of BC [11].