The FGF–FGFR system is hypothesized to be involved in the pathogenesis of COPD, with expression profiles of FGF-1, FGF-2, and FGFR-1 analyzed in bronchial airways of individuals who are current or former smokers, with or without COPD [76]. This evidence concerns the gene FGFR1 and chronic obstructive pulmonary disease.