Although initiated from constitutive activation of Wnt signaling, Hh signaling plays an important role in the maintenance of colon CD133+ CSCs, which display the highest gene expression levels of GLI1, PTCH1, GLI2, SHH and HHIP compared to all CD133− cells in human colon carcinoma samples [83]. This evidence concerns the gene PROM1 and colon carcinoma.