FOS and metabolic dysfunction-associated steatohepatitis: Because it is a key mediator of liver inflammation, the UPR promotes the inflammatory response associated with NASH through the activation of two major inflammatory pathways (JNK)/activator protein 1 (AP1) and IkB kinase (IKK)-NF-κB (Hotamisligil, 2006; Zhang et al., 2006; Zhang and Kaufman, 2008a; Hotamisligil, 2010; Malhi and Kaufman, 2011; Morgan and Liu, 2011; Lee et al., 2012; Lee and Ozcan, 2014; Zhang et al., 2014).