ARG1 and neoplasm: Murine hepatoblastoma-like neoplasms had diffuse immunopositivity for alpha fetoprotein (AFP) and glypican 3 (GPC3), two stem cell markers used to distinguish neoplastic hepatocellular cells39,43,44, as well as immunoreactivity for glutamine synthetase (GLUL or named as GS), a β-catenin target and a marker of β-catenin activated hepatocytes38,39, SALL4, another embryonal type of hepatoblastoma marker45,46, and Arginase-1 (ARG-1), a marker used to distinguish primary hepatocellular tumors from metastatic tumors47.