GPT and Hepatic fibrosis: This study systematically compares serological biomarkers (ALT, AST, ALB, TBIL, PLT, PDW, MPV, INR, CD5L, TGF β1, and GGT) as direct indicators and non-serological biomarkers (AST/ALT ratio, ALBI score, GPR, APRI, INPR, FIB-4, BMI, and FibroQ) as indirect indicators of liver fibrosis across four distinct etiologies—CHB, CHC, ALC, and NALC—highlighting etiology-specific patterns and addressing heterogeneity in fibrosis mechanisms.