AKT1 and gastric cancer: Calcitriol has also demonstrated apoptotic induction via the inhibition of the AKT (v-Akt murine thymoma viral oncogene homolog; protein kinase B)-mediated anti-apoptotic signaling pathway, by means of the upregulation of phosphatase and tensin homolog (PTEN) expression in the HGC-27 gastric cancer cell line [35].