The study of ABC transporters is highly clinically relevant, as mutations in human ABC transporters have been linked to several conditions, including cystic fibrosis, liver disease, tuberculosis, diabetes, macular degeneration, metabolic diseases, and multi-drug resistance (18, 19, 20, 21, 22, 23, 24, 25). Here, ABCG2 is linked to cystic fibrosis.