BRCA1 and breast cancer: Additionally, genetic predisposition also largely contributes to breast cancer initiation, including breast cancer gene 1 and 2 (BRCA1 and BRCA2), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (Her2), phosphatase and tensin homologue deleted on chromosome 10 (PTEN), TP53, c-Myc, and others [2,3].