Steatotic livers also diverge from non-steatotic grafts in their response to the unfolded protein response (UPR) and ER stress, indeed the expression of inositol-requiring enzyme 1 (IRE1) and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) is lower in the presence of steatosis (Ben Mosbah et al., 2010). This evidence concerns the gene ERN1 and steatosis.