This can occur due to the different ways of activation of PI3K pathway by HER-2, HER-3, HER-4 and EGFR activated receptors in HER2 overexpressing tumors [26] and because PI3KCA gene is most frequent mutated gene in triple negative breast cancer, just after TP53 [27]. This evidence concerns the gene ERBB4 and triple-negative breast carcinoma.