Interleukin-7 (IL-7) is a multipotent cytokine belonged to one of the members of IL-2 superfamily. IL-7 has diverse effects on the hematopoietic and immune regulations. IL-7 is a trophic factor that is necessary for both B cell and T cell proliferation and development. In addition, it presents potential antitumor effects in tumors such as glioma, melanoma, lymphoma, leukemia, prostate cancer, and glioblastoma.