TNF and metabolic dysfunction-associated steatohepatitis: In addition, expression of cytokines involved in NAFLD and fibrosis were examined, and in the IU+ group, there was a trend towards an increase in Tgfb1 (Hasegawa et al. 2001) and an increase in Tnf (Crespo et al. 2001), both of which are indicative of more severe NAFLD, oftentimes pointing to NASH.