DDAH1 and metabolic dysfunction-associated steatohepatitis: An FXR agonist is capable of inhibiting asymmetric dimethylarginine (ADMA) accumulation through activating dimethylarginine dimethylaminohydrolase-1 (DDAH-1) expression, thereby increasing the levels of endogenous nitric oxide that regulates NASH progression (Hu et al., 2006; Cunningham et al., 2021).