Treated with CTLA-4 blockade, ICOS expressed higher on CD4+ T cells from peripheral blood and tumor tissues of bladder cancer patients and this CD4+ICOShi T cell population produced higher IFN-γ, indicating that ICOS interacts with CTLA-4 and plays an important role in tumor immunity [14,15]. The gene discussed is IFNG; the disease is urinary bladder carcinoma.