MAPK7 and pulmonary fibrosis: Additionally, extracellular-signal-regulated kinase 5 (ERK5), a member of the mitogen-activated protein kinase (MAPK) family, has recently garnered the attention as the positive regulator of TGF-β signaling, and inhibition of ERK5 ameliorated bleomycin-induced pulmonary fibrosis in mice [17], but the roles of ERK5 in airway fibrosis remain unknown.