While our data does not prove any direct association between induction of the osteopontin gene and dendritic cell infiltration in COPD, it does indicate parallel induction of the osteopontin and CD207 genes occurs in smokers with COPD, and suggests the possibility that cigarette smoke-induced osteopontin levels in the lung may be involved in recruitment or formation of Langerhans type dendritic cells in smokers with COPD. The gene discussed is SPP1; the disease is chronic obstructive pulmonary disease.