In addition, IL-2 has two opposing functions: at low doses, IL-2 tends to stimulate Treg cells expressing high-affinity trimeric receptors (IL-2Rαβγ), resulting in immunosuppression (200, 201); at high doses, after saturation of the receptor on Treg cells, excess IL-2 also interacts with effector T cells via intermediate affinity receptors (IL-2Rβγ) binds to effector T and NK cells, promoting immune activation and anti-tumour responses (202). This evidence concerns the gene IL2 and neoplasm.