FZD4 (frizzled class receptor 4)

Fzd4 is a receptor for Wnt proteins, belonging to the frizzled receptors family. Its stimulation can activate both Wnt/β-catenin canonical and Wnt/Ca2+ non canonical pathways. This receptor plays an important role in the development processes, in particular in the retinal vascularization: it binds the Norrin ligand, a Wnt-unrelated growth factor, and activates β-catenin signalling pathway. Mutations of FZD4 gene are associated with Familial Exudative Vitreoretinopathy (FEVR). Recently dysregulation of FZD4 expression has been reported in different type of cancers, but FZD4 contribution in tumor pathogenesis and progression is still not entirely elucidated.