The receptors of the Ror family are membrane-spanning tyrosine kinases that bind Wnts either alone or as Fzds co-receptors to activate non-canonical Wnt signaling.33,50 ROR1 and ROR2 are also co-receptors for Wnt5a and mostly transduce Wnt/PCP signaling.51–53 Wnt5a can induce ROR1/ROR2 hetero-oligomerization.54 Wnt5a-ROR1/ROR2 signaling is involved in tissue development and cancer.55–57 Moreover, via ROR2, Wnt5a inhibits Wnt3a-induced Wnt/β-catenin signaling.58 This evidence concerns the gene ROR1 and cancer.