When IGFBP-3 or IGFBP-3GGG (an IGFBP-3 mutant which only binds to IGFBP-3R but not IGFs [25]) was overexpressed, a significant induction of apoptosis was observed (Figure 5B), suggesting the existence of a functional IGFBP-3/IGFBP-3R system in CRC. Here, IGFBP3 is linked to colorectal carcinoma.