PIK3CA and breast lobular carcinoma: PIK3CA had mutations in 18% (1625/9020) of tumors (Figure 8C and 8G) and it was frequently mutated in breast mixed ductal and lobular carcinoma 51.72% (45/87) followed by 48.94% of breast invasive lobular (69/141) and 40.47 % of ductal carcinoma (607/1500), respectively Figure 8D.