This suggested exogenous IGFBP-2 inhibited cell growth by sequestering endogenous IGFs and was no longer able to do this in the presence of NBI-31772, which implied an IGF-dependent action of the exogenously added IGFBP-2 on T24 cell proliferation which has been reported in colon cancer [19]. Here, IGF1 is linked to malignant colon neoplasm.