In the present study, we demonstrate that prolonged treatment of several breast cancer cell lines (ZR‐75‐1, CAMA‐1, T47D and BT‐474c) harbouring mutations that activate the Akt signalling pathway with inhibitors of Class I PI3K or Akt leads to marked upregulation of SGK3 mRNA and subsequent activation of the SGK3 protein kinase. The gene discussed is SGK3; the disease is breast cancer.