to exclude possibility that in vivo environment might effect on expression of CD44, the expression of CD44 of primary tumor site in orthotopic liver metastatic model was evaluated by western-blot, as shown in Fig. 1h, similar CD44 expression can be observed compared primary tumor site with in vitro cultured CT26-GFP, taken together, those results indicated that CD44 expression was associated with metastatic propensity in CRC. The gene discussed is CD44; the disease is colorectal carcinoma.