IGHA1 and hepatocellular carcinoma: Collectively, When the IgA1 remains unchanged at protein levels, the fucosylation site occupancy of IgA1[332–353] increases, leading to a rise in IgA1[332–352]-N5H5F1S2 or -N6H3F1S2 and consequently resulting in elevated levels of AAL-reactive IgA1 in HBV-HCC.