GPT and metabolic dysfunction-associated steatohepatitis: Zheng et al., 2020 (40) conducted serum GP73 and cytokeratin-18 M30 fragment testing on 105 patients with biopsy-confirmed MASLD despite persistently normal alanine aminotransferase levels, establishing a non-invasive diagnostic algorithm for nonalcoholic steatohepatitis (NASH) using both markers sequentially, achieving an accuracy of 82.9%.