AKT1 and breast cancer: Specific roles of respective AKT family members have been reported in different cancer settings, and this has been most consistently described for AKT1 and AKT2 in breast cancer; AKT1 is mainly involved in growth and inhibits migration and metastasis, whereas AKT2 activity is not necessarily linked to proliferation but rather drives the invasive and metastatic capacity of different breast cancer models [30,52,61,62,63,64].