GPC1 and hepatocellular carcinoma: McKnight et al. [34] reported that arginase-1 (Arg-1) positivity was demonstrated in 37 of 44 (84.1%) cases of HCC, compared with 32 of 44 cases (72.7%) and 25 of 44 cases (56.8%) for HepPar-1 and glypican-3, respectively.