EPO and colorectal cancer: We demonstrated that Tcf4/β-catenin bound the Hnf4-Responsive Element (Hnf4-RE) in the Epo-3’E and that the enhancer activity is independent of HIF in this context, contrary to what is reported in colorectal cancer cell lines, in which transcriptional cooperation between HIF and β-catenin occurs in hypoxia adaptation (Kaidi et al., 2007).