[30] In these trials, HER2+ BC patients received either trastuzumab or lapatinib, or the combination plus anthracycline-taxane based chemotherapy.[31] The authors found that the pCR rate was lower among HER2+ women with at least one PIK3CA mutation in their tumor, compared with women without a PIK3CA mutation. The gene discussed is PIK3CA; the disease is breast cancer.