The phosphoinositide 3-kinase (PI3K) pathway, which is hyperactive in more than 70% of breast cancers due to oncogenic activating mutations (e.g., Pik3caE545K, Pik3caE542K and Pik3caH1047R), amplification of the alpha catalytic subunit, or the genetic loss of tumor suppressors (Pten), is a major driver of cell transformation [58–60]. This evidence concerns the gene PIK3CA and breast carcinoma.