Lentivirus-mediated silencing of IGF-1R in IGF-1R+ BC0145 or IGF-1Rhi BC0244 cells suppressed their tumorigenicity in NOD/SCID mice, with tumor formation in only one out of four mice by week 9 after injection of sh-IGF-1R transduced IGF-1R+ BC0145 cells, and no tumor formation up to week 15 after injection of sh-IGF-1R transduced IGF-1Rhi BC0244 cells. Here, IGF1R is linked to neoplasm.