To investigate the impact of inhibition of PI3K/Akt/mTOR axis pathway on the chemosensitivity of canine tumours, we evaluated the effects of the combination of the class I PI3K pathway inhibitors and Doxorubicin on the viability of canine SB and REM cells and utilized the Bliss additivism model to analyze the effects. The gene discussed is AKT1; the disease is neoplasm.