PIK3CA and breast cancer: We then compared the differences between oncodriver genes using the Catalog of Somatic Mutations in Cancer database (http://cancer.sanger.ac.uk/census) and found that 44% (141/320) of the genes had a lower mutation rate in the IP5 group than in the other IP groups, including breast-cancer-specific oncodriver genes (TP53, ERBB2, MAP3K4, BRCA1, ERBB4, and PIK3CA).