sentences:  Club cells in the terminal bronchioles convert the 3-methylindole to 3-methyleneindolenine, which is toxic to the adjacent alveolar epithelial cells.This toxicity leads to emphysema and pulmonary edema which may cause death by asphyxiation.In the history of research into this causative pathway, the roles of L-tryptophan and indoleacetic acid to 3-methylindole were identified as early as 1967 and 1972.