In recent years, immunotherapy has made historic breakthroughs in the treatment of a variety of tumors, among which PD-1/PD-L1 inhibitors have been applied in a variety of malignant tumors.[1] The binding of PD-1 and PD-L1 inhibits the proliferation of T cells and affects their survival of T cells by suppressing the production of interferon-γ, tumor necrosis factor-α, and interleukin-2. Here, IL2 is linked to cancer.