PIK3CB and breast cancer: On the other hand, genomic aberrations observed in the PI3K pathway in breast cancer include also activating alterations, involving the AKT and loss/mutation of PTEN [19, 20].The prevalence of AKT1 mutation (E17K) in breast cancer is 8%, which has been shown to lead to notable kinase activity than that of wild-type AKT1 [21].