AKT1 and cancer: The previous studies revealed that PI3K/AKT/mTOR signalling pathway play crucial role in the pathogenesis of ESCC.20, 21 PIK3CA is a subunit of PI3K and often responsible for the activity of PI3K/Akt/mTOR signalling pathway.22 Mutation of PI3KCA could cause neoplastic transformation and accelerate cancer progression.23, 24 Shigaki et al25 have demonstrated that PIK3CA mutation is significantly associated with a favourable prognosis of patients with ESCC after curative resected treatment.