There was no difference in pCR rates in patients with either PIK3CA-mutated tumours or ERBB family-mutated tumours compared with patients with WT tumours in either the TCH or the TCHL arm (Fig. 4a and b); however, when we combined PIK3CA and ERBB family mutations, in the TCHL arm, the pCR rate was higher for 9 patients whose tumours harboured a PIK3CA and/or an ERBB family mutation compared with 20 patients with WT tumours (77.8% vs. 35%; p = 0.05) (Fig. 4c). Here, PIK3CA is linked to neoplasm.