IL1B and chronic obstructive pulmonary disease: This distinguishes from the absence of changes in COX1 expression after interleukin 1b (IL-1b) and tumor necrosis factor (TNF-α) stimulation, after which the rise in basal expression was completely triggered by COX1, whereas the notable boost in COX activities of COPD fibroblasts was triggered by COX2, suggesting that COX1 might make up for the boosted basal synthesis of PGE2.