IGF1 and neoplasm: To examine whether IGF-1 production was related to IL-15 stimulation, CD45+ CD11b+ Gr-1+ CD215+ and CD45+ CD11b+ Gr-1+ CD215− cells were sorted from tumor tissue and cultured for 72 h in medium with IL-15, anti-IL-15 antibody (αIL-15) or anti-CD215 antibody (αCD215).