As it is known that the disruption of ER homeostasis is linked to animal models of fatty liver disease (26, 27), the aim of this study was to investigate the effects of the OTR/down, OTR/up, and OTR protocols on the proteins related to ER stress (i.e., BiP, IRE1, PERK, eIF2alpha, ATF6beta, and GRP94) and apoptosis (CHOP, Caspase-3, 4, and 12, Bax, and TRAF2) in livers of C57BL/6 mice. This evidence concerns the gene ERN1 and fatty liver disease.