DDIT3 and hepatocellular carcinoma: In contrast with these reports, melatonin has been reported to inhibit tunicamycin-induced ER stress in human hepatocellular carcinoma cells and increase the response of these cells to cytotoxic effects of doxorubicin; this is accompanied by inhibition of the PI3K/AKT pathway, elevation of CHOP and reduction of Survivin [79].