Except for the TP53 genetic mutations, which were found in all cancer types, we observed the highest percentages of mutations in ERBB2 and PIK3CA in breast cancer, KRAS and PIK3CA in colorectal cancer, PTEN and PIK3CA in endometrial cancer, CDKN2A and HRAS in oral cancer, BRCA1 and BRCA2 in ovarian cancer, and KRAS and CDKN2A in pancreatic cancer. The gene discussed is PTEN; the disease is breast cancer.