Tumour‐associated Treg cells are known to express numerous co‐stimulatory (i.e. ICOS, OX40, GITR) and co‐inhibitory (i.e. Lag‐3, Klrg1, Tim‐3, TIGIT, PD‐1) receptors that modulate their function (Fig 2). The gene discussed is HAVCR2; the disease is neoplasm.