We examined the role of nardilysin, that is known to enhance TNF-α shedding, in the development of steatohepatitis using Nrd1+/+ and Nrd1−/− mice fed a choline-deficient and amino acid-defined (CDAA) diet and a high-fat diet (HFD), that are used widely to reproduce the natural course of NASH and liver fibrosis in mice as well as in humans. The gene discussed is TNF; the disease is metabolic dysfunction-associated steatohepatitis.