4C8A:
reference: Structural and molecular basis of ZNRF3/RNF43 transmembrane ubiquitin ligase inhibition by the Wnt agonist R-spondin., Zebisch M, Xu Y, Krastev C, Macdonald BT, Chen M, Gilbert RJ, He X, Jones EY, Nat Commun. 2013 Nov 14;4:2787. doi: 10.1038/ncomms3787. PMID: 24225776

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