GPC3 and hepatocellular carcinoma: When revealing for the first time that GPC3 promotes HCC growth through the activation of the canonical Wnt pathway, Filmus J’s team also elucidated that GPC3 lacking HS chains, the GPC3ΔGAG mutant, retains the ability to interact with Wnt3a and activate its signaling to promote HCC growth, suggesting that the HS modification at the C-terminus of GPC3 is not required for its activation of Wnt signaling and HCC-promoting effects [82].