NFKB1 and cystic fibrosis: While NF-κB is the principal activator of IL-8 production, other transcription factors, such as Activating Protein (AP)-1 [46] and Mitogen-Activated Protein Kinases (JNK, p38 MAPK, and ERK) [47] are involved in up-regulation of IL-8 in response to CF-relevant stimuli.