In colorectal cancer (CRC), down-regulation of miR-497 caused by the DNA copy number reduction of chromosome 17p13.1 would up-regulate the IGF-1R or IRS1, and activate PI3K/Akt signaling, contributing to the survival of CRC cells by promoting tumor growth and resistance to chemotherapy [64,65]. Here, IRS1 is linked to colorectal carcinoma.