STAT3 and cancer: The radio-sensitivity of curcumin is attributed to its influences on various molecules involved in the cellular signaling pathway, including PI3-kinase, NF-κB, STAT3, COX2, Akt, MAPK, AMPK, p53, Nrf2, Notch-1, β-catenin, and the upregulation of genes responsible for cell death that induce apoptosis and inhibit proliferation of cancer cell (Shehzad & Lee, 2013a).