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). This evidence concerns the gene KLRG1 and neoplasm.