BIO (GSK-3 Inhibitor IX, 6-bromoindirubin-3-oxime, 6-Bromoindirubin-3′-oxime, MLS 2052) is a specific inhibitor of GSK-3 with IC50 of 5 nM for GSK-3α/β in a cell-free assay, shows >16-fold selectivity over CDK5, also a pan-JAK inhibitor with IC50 of 30 nM for Tyk2. BIO induces apoptosis in human melanoma cells.