Pathogenic variants in the genes that encode SP-B and SP-C (SFTPB and SFTPC) and genes that are involved in surfactant production (ABCA3 and NKX2-1) result in surfactant dysfunction disorders, one of the genetic causes of interstitial lung disease (ILD) (10, 19, –21). This evidence concerns the gene SFTPB and interstitial lung disease.