Recent studies have demonstrated that the anti-Fzd7 antibody [12, 19, 20, 21], siRNA/shRNA knockdown of Fzd7, [6, 7, 12, 15, 16, 17], soluble Fzd7 peptides [22] and small interfering peptides directed against Fzd7 [23] antagonized Wnt/β-catenin signaling in Fzd7-expressing cancer cells, and suppressed tumor progression and metastasis. Here, FZD7 is linked to cancer.