- The expression of HAVCR2 increases with age across diverse tissues in normal and cancer tissues. - Prolonged exposure to cancer-related stimuli alters numerous T cells, prompting an elevation in the expression of co-inhibitory receptor HAVCR2.- Immunosenescence is characterized by higher levels of HAVCR2 in the T cells of elderly patients.- HAVCR2 upregulation renders T cells less responsive and impairs their reactivity. The gene discussed is HAVCR2; the disease is cancer.