Furthermore, azithromycin has been shown to improve respiratory function in cystic fibrosis patients [94] and the study by Gillis et al. [93] shows that the MexAB-OprM and MexCD-OprJ pumps may play a critical role in the formation of biofilms in cystic fibrosis lungs during azithromycin therapy. Here, OPRM1 is linked to cystic fibrosis.