The most commonly altered genes in 36 patients with breast cancer were TP53 (n = 20/36, 55.6%), PIK3CA (n = 14/36, 38.9%), ATM (n = 6/36, 16.7%), and BRCA1/2 (n = 4/36, 11.1%). This evidence concerns the gene PIK3CA and breast carcinoma.