IGFBP5 and neoplasm: Remarkably, IGFBP5 inhibited tumor growth in IGFBP5 OE mice significantly (mean tumor weight: 0.018 ± 0.008 g, *, p < 0.05), whereas the tumors of the control group grew far larger (mean tumor weight: 1.73 ± 0.46 g) (Figure 2D).