Endotracheal intubation and tracheotomy are widely used in the hospital setting for elective surgery and in cases of serious illness or critical injury. In rare instances the procedures result in the development of scarring and narrowing of the larynx and trachea, or acquired laryngotracheal stenosis (ALTS). Who is susceptible to ALTS — and why — is unclear, but according to new research, genetic and ethnic background may be underlying factors.