For instance, Arg-1 demonstrates superior sensitivity (85.7%) in poorly differentiated HCC compared to HepPar1 (46.4%) [11], but its occasional reactivity in cholangiocarcinoma (6.9%) [152] necessitates integration with GPC3 (specificity 97.3%) or pCEA (canalicular pattern specificity). The gene discussed is GPC3; the disease is cholangiocarcinoma.