TAK1 activates IKK complex that phosphorylates inhibitory proteins (IκBε, IκBα) causing dissociation from transcription factors (RelA, cRel, NF-κB1, NF-κB2). Phosphorylated inhibitory proteins are degraded via the proteasome, and the transcription factors are imported into the nucleus to activate expression of target genes [41]. Inhibitory activity of PP6 on NF-κB signaling can occur in at least two ways: (1) by dephosphorylation and inactivation of TAK1 or (2) by dephosphorylation of the IκBε inhibitory protein.