AKT1 and cancer: Phosphorylation, by either PKA or the Ser/Thr kinase AKT (protein kinase B), blocks PDZ-PBM binding and allows E6 to directly interact with the 14-3-3 zeta protein (Figure 4), a protein involved in the regulation of cellular processes (signal transduction, cell cycle regulation, and apoptosis) that are related to cancer progression [72].