The nuclear factor-κB (NF-κB) pathway is one of the most important cellular signal transduction pathways involved in both physiologic processes and disease conditions. It plays important roles in the control of immune function, inflammation, stress response, differentiation, apoptosis, and cell survival. Moreover, NF-κB is critically involved in the processes of development and progression of cancers. More importantly, recent studies have shown that NF-κB signaling also plays critical roles in the epithelial-mesenchymal transition (EMT) and cancer stem cells. Therefore, targeting of NF-κB signaling pathway could be a potent strategy for the prevention and/or treatment of human cancers and inflammatory diseases.