Given that HLJ1 deficiency potentially alters hepatic gene expression patterns related to xenobiotic metabolism and chemical-induced tumor incidence, we utilized diethylnitrosamine (DEN), a well-established carcinogen that induces mouse liver cancer resembling human HCC (Lee et al. 2004), to clarify the role of HLJ1 in hepatocarcinogenesis. The gene discussed is DNAJB4; the disease is hepatocellular carcinoma.