For example, Levy et al. found that the intratumour injection of low-dose cytosine–phosphate–guanine oligodeoxynucleotides (CpG-ODNs) induces the expression of OX40 on CD4+ T cells, and the combination of CpG with agonistic anti-OX40 antibody further enhances the antitumour effect of immune cells, systematically shrinking the tumours in mice, particularly lymphoma [12]. The gene discussed is CD4; the disease is neoplasm.