NF-κB activity in MM cells. MM cells express both canonical and noncanonical NF-κB activity. In MM cells, both canonical and noncanonical NF-κB pathways are activated, and there is possible cross-talk signaling between each pathway. BMSCs activate canonical and noncanonical NF-κB pathways in MM cells. Both canonical and noncanonical pathways should be blocked to inhibit total NF-κB activation in the context of the MM microenvironment. IKKα knockdown induces down-regulation of β-catenin and Aurora-A expression independent of NF-κB inhibition.