CFTR and cystic fibrosis: Pulmonary disease caused by NTM usually occurs in individuals that are sensitized by other lung-associated diseases, such as chronic obstructive pulmonary disease (COPD), changes in lung and chest architecture, α-1-antitrypsin deficiency, cystic fibrosis, heterozygosity for cystic fibrosis transmembrane conductance regulator (CFTR) mutations, gastric reflux disease, rheumatoid arthritis, and immunodeficiency or immunosuppression due to human immunodeficiency virus (HIV) infection, organ transplant, cancer, or chemotherapy [73].