GSK-3β’s role in apoptosis signaling. The above schematic shows the role of activated GSK-3β and its role in regulating apoptosis. Active GSK-3β inhibits MDM2 regulation of p53, leading to DNA repair and growth arrest, and in some cases the activation of the caspase cascade through Bax to promote apoptosis. Active GSK-3β also positively regulates NFκB by activating IKK, IκB, and p65, leading to the inhibition of TNF-mediated apoptosis. These actions inhibit the initiation of apoptosis through the TNF signaling cascade.