Cystic fibrosis is a common genetic disease, relatively speaking. About one in 25 to 30 Caucasians are carriers of a cystic fibrosis mutation. But there are more than 1,700 mutations of the cystic fibrosis gene that can result in different disease symptoms. Researchers and companies working on cystic fibrosis treatments are increasingly paying attention to which mutations a patient carries, and tailoring drugs to certain mutations. Just recently, the FDA expanded its approval for one cystic