In the present study we investigated the expression, localization and clinicopathologic correlations of IRS1 ex vivo, in cancer-uninvolved human colonic epithelium, primary CRCs and paired liver metastases, and in vitro, in two CRC cell models capable of spontaneous in vitro polarization, Caco2 and HT29 [22], [23]. This evidence concerns the gene IRS1 and colorectal carcinoma.