In conclusion, YKL-40 expression is enhanced in numerous local inflammatory processes, including OSAS and chronic liver diseases, but the role of this protein in NAFLD development and progression needs to be clarified; moreover, further studies are needed to elucidate if the OSAS-dependent YKL-40 increase could trigger liver injury or affect the progression of a concomitant liver disease. The gene discussed is CHI3L1; the disease is metabolic dysfunction-associated steatotic liver disease.