RPS6KA1 and neoplasm: In contrast, KC3 tumours displayed the highest activation of the PI3K‒AKT‒mTOR signalling pathway, as evidenced by elevated PI3K, phospho (p)‐AKT (S473), p‐PRAS40 (T246), p‐mTOR (S2448), P90RSK and reduced 4EBP1 levels (Table S5 and Figure S6F).