A potent and selective inhibitor of GSK3 (IC50s = 1.5 and 0.9 for human recombinant GSK3α and GSK2β, respectively); has >10-fold selectivity for GSK3 against a panel of 40 kinases at a concentration of 20 μM; induces time-dependent stabilization of β-catenin total protein and activates Wnt signaling in vitro; has potent antiproliferative activity in BRAF wild-type/NRAS mutant and BRAF mutant melanoma cell lines (IC50s = 6.0-11.8 nM) but has limited to no activity in non-melanoma cell lines (IC50s = 430 to >20,000 nM); knockdown of β-catenin in A375 and M14 melanoma cells induces LY2090314 resistance in vitro; reduces tumor volume in a murine A375 xenograft model as a single agent and synergizes with decabarzine for a greater antitumor effect,