The R-spondin family of proteins: Emerging regulators of WNT signaling
Keywords: BA, branchial arch; BMP, bone morphogenetic protein; BR, basic amino acid-rich; CR, cysteine-rich; DKK1, dickkopf homolog1; Dlx, distal-less homeobox; EIF3E, eukaryotic translation initiation factor 3 subunit E; EGF, epidermal growth factor; FGF, fibrobla