In subgroup analyses, AFP, PIVKA-II, AFP + PIVKA-II, and AFP + AFP-L3 + PIVKA-II + ALT + Age models showed good capabilities in differentiating HCC from chronic hepatitis (AUC values were 0.814, 0.869, 0.885, and 0.922, respectively, Additional file 4: Table S4). This evidence concerns the gene AFP and hepatocellular carcinoma.