IRS1 and metastatic neoplasm: Primary and metastatic tumors, when compared to colonic epithelium, contained higher numbers of cells expressing IRS1 (80.8±6.2% for primary and 81.3±6.6% for metastatic CRC versus 59.1±5.6% for colonic epithelium, P = 0.013 and P = 0.014, respectively, Figure 2F).