AKT1S1 and neoplasm: Several components of the AKT pathway were specifically activated in the tumor-derived cells, including AKT, PRAS40, and GSK3α/β, consistent with this pathway being activated due to amplification of RICTOR and PIK3CA. High levels of phosphorylation were also found for the p53 tumor suppressor protein, and the WNK1 protein kinase (Fig. 1c).