TNF and metabolic dysfunction-associated steatotic liver disease: Mc1r LKO mice showed a tendency towards increased expression of interleukin-1 beta (Il1b) as well as significant upregulation of interleukin 6 (Il6) and tumor necrosis factor alpha (Tnfa), which are key pro-inflammatory cytokines regulating hepatic inflammation in NAFLD [36] (Fig. 5D).