It remains possible that co-activators such as p300, necessary for transcriptional induction of Cox-2 by NF-κB [63], are repressed by RelB or altered in COPD, thereby accounting for differences in Cox-2 between At Risk and COPD fibroblasts or the initiation of Cox-2 transcription after RelB knock-down. This evidence concerns the gene PTGS2 and chronic obstructive pulmonary disease.