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 TIGIT; the disease is neoplasm.