Xenografts experiments of Rat2 fibroblasts transduced with a myristoilated-Akt version and either a vector control or a vector expressing Flag-Beclin 1 (wild-type or S234/295A) indicate that activated Akt was able to transform fibroblast to fibrosarcomas, that Beclin 1 wild-type overexpression prevents tumor growth, and that this effect is further enhanced by overexpressing the Beclin 1 S234/295A non-phophorylatable mutant. The gene discussed is AKT1; the disease is fibrosarcoma.