IGF1 and neoplasm: To further investigate whether IGF-1 facilitate tumor growth in our study, we sorted CD45+ CD11b+ Gr-1+ CD215+ and CD45+ CD11b+ Gr-1+ CD215− cells from the spleen of tumor-bearing mice and cultured them with A549-GFP-luciferase cells with IL-15 or IL-15 plus anti-IGF-1 antibody.