When we included patients with low tumour expression of PTEN, there was no difference in pCR rates in patients whose tumours had a PIK3CA/ERBB family mutation and/or low PTEN expression (i.e., PI3K activated) compared with patients with WT tumours in either the TCH or the TCHL arm (Fig. 4d and e). This evidence concerns the gene PTEN and neoplasm.