PIK3CA and invasive breast carcinoma: As previously [17], for this analysis, we used the following list of 10 protein-coding genes with an established role in BrCa pathophysiology, namely, BRCA1 [26], BRCA2 [26], RASSF1 [27], ESR1 [28], TP53 [29], PIK3CA [30], BRMS1 [31], CDH1 [32], CST6 [33] and PTEN [34].