MTOR and neoplasm: While overexpression of p-S6 (Ser 235/236) was elevated in the two patients harbouring PIK3CA mutations, staining intensity of p-AKT, p-mTOR, p-S6 (Ser 235/236), p-S6 (Ser 240/244) and p-4EBP1 did not correlate across the tumours, indicating a complex mode of pathway activation.