PTEN is a negative regulator of the PI3K/AKT pathway through its dephosphorylation of the inositol triphosphate activator of AKT, a tyrosine kinase that participates in a wide range of cellular behaviors, including: regulation of the cell cycle, proliferation, apoptosis, cell adhesion, epithelial-to-mesenchymal transition (EMT) and cancer progression. The gene discussed is AKT1; the disease is cancer.