GPC3 and cholangiocarcinoma: As reported in the literature, G3 poorly differentiated HCCs are primarily characterized by the loss or focal expression of HepPar1, along with partial or heterogeneous expression of Glypican-3, while they may re-express markers such as CK7 and focal CK20, features typical of certain G3 HCC subclasses with a combined hepatocellular–cholangiocarcinoma phenotype [20,21] (Figure 4A).