Regulatory T (Treg) cells, known suppress immune effector cell activity and promote tumour immune escape,49, 50 were divided into two subgroups: one expressing FOXP3 and IL2RA (also known as CD25) and marked by TNFRSF9,51 indicating activation, and the other showing IFIT1 and IFIT3, suggesting responsiveness to interferons. This evidence concerns the gene TNFRSF9 and neoplasm.