WNT2B and major depressive disorder: WNT2B and FZD7 are elements of the canonical WNT signaling pathway regulating neurogenesis, synaptic plasticity and dendritic arborization.32 Downstream growth factors such as FGF, BDNF and BMP are involved in depression pathogenesis as well as in the maintenance of adult neurogenesis.33, 34, 35 WNT2B is a highly conserved signal peptide and a ligand for members of the frizzled transmembrane receptor family; FZD7 belongs to this family of GPCRs.