PKN1 and melanoma: In the cell membrane, regulating RNF43/ZNRF3 and RSPO results in accumulation of LRP5/6 and Fz receptors, making the Wnt receptors more sensitive and promoting the Wnt signaling pathway in spite of low concentration of Wnt proteins [32], whereas phosphorylation of LRP6 by WNT 3 is inhibited by protein kinase N1 (PKN1) and is more sensitive to cell death in melanoma cells [57].