DPP4 and metabolic dysfunction-associated steatotic liver disease: The cell-surface aminopeptidase DPP4 has a multifunctional serine protease activity that is involved in metabolizing substrates and has been implicated in several metabolic disorders including non-alcoholic fatty liver disease, or as several experts now call it, metabolic dysfunction-associated steatotic liver disease (MASLD) [4], cardiovascular disease, and obesity [[5], [6], [7], [8]].