PIK3CA and breast carcinoma: Furthermore, some breast cancer subtypes are associated with particular somatic mutations; somatic mutations in only three genes (Tumor Protein P53 (TP53), Phosphatidylinositol-4,5-Bisphosphonate 3-Kinase Catalytic Subunit Alpha (PIK3CA), and GATA Binding Protein 3 (GATA3)) are represented at >10% incidence across all subtypes [20].