AKT1 and breast cancer: One of the Akt isoforms, Akt1, can exert an antimetastatic effect, which is accompanied by increased ERα expression.164 Breast cancer cells undergo differentiation upon the activation of Akt1, thereby losing their metastatic potential.165 Similarly, Akt1 can inhibit metastasis in mice by regulating MMP9 and E-cadherin.166