Through bioinformatics analyses, Sun et al. (2021) found that the zinc finger protein 2 gene (ZIC2) is positively correlated with immune infiltrating cells in hepatocellular carcinoma (HCC) patients, and elevated ZIC2 mRNA expressions in CD4+ T cells are associated with the 5-year survival rate of HCC patients. The gene discussed is CD4; the disease is hepatocellular carcinoma.