DDIT3 and hepatocellular carcinoma: Since treatment with TM significantly induced both mRNA and protein expression of CHOP in Heap 1–6 cells (Fig 4A), to figure out whether CHOP also influences ER stress-induced apoptosis in HCC cells, a self-prepared lentiviral system was used to achieve a specific knockdown of CHOP in Hepa 1–6 cells.