A closer look
Your lungs are secretly trying to drown you in biological cement. Airway mucus hypersecretion goes terribly wrong in cystic fibrosis because of a tiny genetic typo in the CFTR gene. Normally, this protein pumps chloride ions out of your cells to draw water into your mucus, keeping it thin and sweeping away dirt. The mutation breaks the pump, leaving the mucus totally dehydrated. It turns into a sticky, immovable sludge that collapses airways and creates the perfect anaerobic breeding ground for deadly, chronic lung infections.
