SIRT1 and metabolic dysfunction-associated steatohepatitis: Besides, we found that the protein expression levels of eNOS, p‐eNOS, and SIRT1 were significantly decreased in MASH livers and were at lowest levels in aged MASH patients (Figure 4C,D) suggesting that aged MASH patients predispose more severe LSECs dysfunction, liver injury, and fibrosis with accompanied decrement in hepatic SIRT1 levels in accordance with the observations from rodent MASH model.