Visceral adipocyte-derived exosomes from obese individuals carry miR-23b, miR-148b, miR-4269, and miR-4429 into hepatocytes and upregulate the expression of TIMP-1, TIMP-4, Smad-3, and MMP-9, thereby inducing abnormal regulation of the TGF-β signaling pathway and leading to the progression of NAFLD to hepatic fibrosis (63). Here, MMP9 is linked to metabolic dysfunction-associated steatotic liver disease.