Ivacaftor is a medication taken by mouth for the treatment of CF due to a number of specific mutations responsive to ivacaftor-induced CFTR protein enhancement. It improves lung function by about 10%; however, it is expensive. The first year it was on the market, the list price was over $300,000 per year in the United States. In July 2015, the U.S. Food and Drug Administration approved lumacaftor/ivacaftor. In 2018, the FDA approved the combination ivacaftor/tezacaftor; the manufacturer announced a list price of $292,000 per year. Tezacaftor helps move the CFTR protein to the correct position on the cell surface, and is designed to treat people with the F508del mutation.