Figure 6: A canonical Wnt signaling pathway. In the presence of Wnt, the signals are transduced through Frizzled family receptors and LRP5/LRP6 coreceptor to the -catenin signaling cascade which then stabilize hypophosphorylated -catenin and interact with TCF/LEF, Legless and PYGO for target gene activations. MARK and CKI are the positive regulators of canonical Wnt pathway, while APC, AXIN1, AXIN2, CKI , NKD1, NKD2, TRCP1, TRCP2, and ANKRD6 are negative regulators. In the absence of Wnt, -catenin-forming complex with AXIN and APC is phosphorylates, leading to be a target for ubiquitination and degradation by proteasome (adapted from [16]).