Serum IgM-free AIM levels were significantly higher in both the NASH-HCC patient group and the viral HCC patient group, and both ROC analysis and the diagnostic accuracy of IgM-free AIM demonstrate that serum IgM-free AIM may be a potential universal HCC diagnostic marker that could be superior to AFP or DCP, even in early cancer stages. Here, AFP is linked to metabolic dysfunction-associated steatohepatitis.