We noticed that the mRNA level of EGFR (p = .011), ERBB2 (p = .028), ERBB4 (p = .003) and IGF‐1R (p = .001) were significantly down‐regulated in PIK3CA mutant cells (Figure 4F), which is consistent with TCGA dataset with lower transcriptome expression level of ERBB2 and IGF‐1R in HER2+ tumours harbouring PIK3CA H1047R mutations. This evidence concerns the gene ERBB4 and neoplasm.