DDIT3 and steatosis: ER stress in NAFLD and steatosis generally plays a vicious role directly or indirectly via the induction of de novo lipogenesis and perturbation of mitochondrial biogenesis.59 Oleic acid induction to HepG2 cells was found to increase the protein and gene expression of p-PERK, p-IRE-1, ATF 6 and p-eIF2α, a downstream target of PERK and CHOP.