EPHX1 and lung cancer: Bartsch et al. (1992) observed a significant increase in the activity of pulmonary EPHX1 within smokers, but EPHX1 activity was determined in preparations of parenchymal lung tissue, which consists of many different cell types. Besides, the lung tissue specimens were taken from patients with either lung cancer or non-neoplastic lung diseases. Thus, a direct comparison between the present study and that of Bartsch et al. (1992) cannot be made.