A pre-assembled complex consisting of Sdc1, inactive αvβ3 or αvβ5 integrin and inactive IGF-1R is found in fibroblasts, breast cancer and other carcinomas, multiple myeloma and activated vascular endothelial cells undergoing pathological angiogenesis (39–42) (Figure 1) and is likely found in many cancers. Here, SDC1 is linked to breast carcinoma.