Although evidence has been building that Frizzled-7 is an important cell surface receptor governing Wnt signaling in cancer cells and accelerating cancer development and progression, Frizzled-7 is not exclusively expressed in cancer tissue but is also expressed and plays an important role in stem cells, such as embryonic stem cells and LGR5+ colonic crypt cells [54, 55]. This evidence concerns the gene FZD7 and cancer.