 Nontuberculous mycobacteria NTM are ubiquitous environmental organisms. NTM lung disease is increasing, however, genetic susceptibility of patients with the disease have not been identified. To elucidate the genetic susceptibility of NTM lung disease, the investigators perform a genome-wide association study GWAS including patients with NTM lung disease and healthy controls case : control 1 : 3. The age-, sex-matched control group will be recruited from the Korean Healthy Twin Study. 