IL2 and renal cell carcinoma: At present, systemic drug therapy is the main treatment for Metastatic renal cell carcinoma (mRCC), including targeted drug therapy and immunotherapy [21].Before the advent of molecular targeted drugs, biological immunotherapy with interleukin-2 (IL-2) and interferon-α (IFN-α) was mainly used for advanced RCC [22], with an objective response rate of less than 30%, an mPFS of only 5 months [23], and a five-year survival rate of 8% for patients with mRCC [24].