On the other hand, several other reports offered a different view about the expression and activity of secreted Wnt antagonists in the tumor setting [33], saying that the upregulation of WIF-1 expression was detected in colonic adenoma and CRC cell lines, along with the loss of expression of other inhibitors such as SFRPs and Dkk-1 [34], and that the Drosophila ortholog of WIF-1 facilitated hedgehog diffusion, thus raising the possibility that mammalian WIF-1 may enhance hedgehog activity [35, 36]. This evidence concerns the gene DKK1 and colon adenoma.