CYP1B1 and chronic obstructive pulmonary disease: In sputum macrophages of healthy non smokers (Fig. 4B) we showed a 4-fold and of COPD patients a 3-fold reduction of CYP1B1. One of the COPD patients currently smoked and showed a high level of CYP1B1 mRNA in untreated sputum macrophages that was not affected after ultrafine P90 treatment.