In different breast cancer subtype cell models, all sharing high activity of AKT signal depending from PI3Ka activating mutation, including cells harbouring various expression profile of HER2 and HR receptors, we demonstrated a synergistic effect of combination of taselisib or of ipatasertib and anti-microtubule agents in terms of anti-proliferatve effect. The gene discussed is ERBB2; the disease is breast cancer.