Altogether, our data suggest the following: (a) changes in leukocyte MMP/TIMP expression profiles are mostly unrelated to their plasma levels but may represent early markers of leukocyte subset activation that eventually may precede the subsequent liver response to damage in the early stage of NAFLD, and (b) the subsequent increase in plasma levels of MMP-9 and TIMP-1 as well as the elevation of MMP-9/TIMP-1 ratios may reflect NAFLD's progress towards fibrosis, which is in agreement with the recent data on the role of TIMPs (especially TIMP-1) in the regulation of the matrix turnover [38]. Here, TIMP1 is linked to metabolic dysfunction-associated steatotic liver disease.