In honor of our future work on membrane proteins, I thought I’d share a little bit about cystic fibrosis, an autosomal recessive disease that affects 30,000 Americans. Most people are diagnosed by age 2 and life expectancy is typically in the 40s. It’s actually the most common autosomal recessive disease for Caucasians, although it’s prevalent in all races, and thousands of people are carriers. Cystic fibrosis is caused by mutations in chloride ion channels, part of the ATP-binding cassette (ABC) transporters used by cells to regulate water levels inside and outside the cell. Because water can’t be regulated by the cells anymore, thick mucus builds up, crushing cilia that line the lungs, pancreas, reproductive tract, and many other surfaces. This mucus is a great environment for bacteria to grow, and cystic fibrosis patients are often infected by pathogens like P. aeruginosa, making the quality of life even worse than it already is, as the mucus makes it hard for patients to breathe and often makes both men and women infertile.