Activator of the beta-catenin signaling cascade, leading to TCF-dependent gene activation. Acts both in the canonical Wnt/beta-catenin-dependent pathway and in non-canonical Wnt signaling pathway, probably by acting as an inhibitor of ZNRF3, an important regulator of the Wnt signaling pathway. Defects in RSPO4 are the cause of nail disorder non- syndromic congenital type 4 (NDNC4). A nail disorder characterized by congenital anonychia or its milder phenotypic variant hyponychia. Anonychia/hyponychia is the absence or severe hypoplasia of all fingernails and toenails without significant bone anomalies. Belongs to the R-spondin family. 2 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Protein type: Cell development/differentiation; Secreted; Secreted, signal peptide