MAPK8 and chronic obstructive pulmonary disease: These data indicate that p38MAPKα, ERK, and JNK are involved in the regulation of the expression of IL-8 but that only p38MAPKα (but not the γ isoform) is involved in the mechanism of the corticosteroid insensitivity of IL-8 in this cell culture model of exacerbated COPD.