For its endosomal signaling, quiescin sulfhydryl oxidase 1 (QSOX1) has been identified as a cellular pro-oxidant, which accelerates ubiquitination-mediated degradation of EGFR and its intracellular endosomal trafficking in hepatocellular carcinoma (HCC) cells [61]. The gene discussed is EGFR; the disease is hepatocellular carcinoma.