GPT and metabolic dysfunction-associated steatotic liver disease: Non-invasive biomarkers for NAFLD encompass serum-based indicators (e.g., alanine alanine aminotransaminase (ALT), serum aspartate aminotransferase (AST), cytokeratin-18), imaging modalities (e.g., transient elastography, MRI), and clinical prediction models (e.g., NAFLD fibrosis score, FIB-4 index) (Figure 1).