IL-2, IL-10, IL-33, and IL-21 can promote tumor growth and metastasis (29–34).However, the efficacy of IL-15, IL-8, and IL-17A/F, which have been utilized in clinical practice, is limited (35–38), Furthermore, IL-2 may also cause side effects, such as chills, high fever, capillary leakage, respiratory distress, liver and kidney damage, etc. (39).IL-2 demonstrated its therapeutic potential through persistent complete response in melanoma (40). The gene discussed is IL21; the disease is neoplasm.