NFKB1 and cystic fibrosis: Recently, P. nigrescens and P. histicola were reported to diminish NF-κB (p65) signaling and levels of cytokines, such as IL-6 and IL-8, induced by P. aeruginosa in CF airway epithelial cells (CFBE41o- cells) by reducing P. aeruginosa growth (53).