In view of the inconsistent published findings with the allosteric AKT inhibitor MK-2206, and the lack of in vivo studies in cancer models, we set out to assess the metabolic changes in response to MK-2206 both in vitro and in vivo in subcutaneous and orthotopic animal xenograft models of colon and prostate cancer, with potential to develop these metabolic changes as non-invasive biomarkers for monitoring response in clinical trials. The gene discussed is AKT1; the disease is prostate cancer.