This study has successfully provided evidence that 1) CD166-pcc has more KRAS exon 2 mutations than CD166-ncc in CRC and hotspot KRAS exon 2 mutations were detected in CAD and 2) these KRAS exon 2 mutations in CD166 positive cells may have prognostic significance in patients with CRC. The gene discussed is KRAS; the disease is colorectal carcinoma.