Unlike in rodents that have a single gene encoding surfactant protein A (SP-A), in humans SP-A consists of SP-A1 and SP-A2 encoded by SFTPA1 and SFTPA2, respectively; each gene has been identified with several genetic variants (14), and these have been shown to associate with several pulmonary diseases (15, 16). This evidence concerns the gene SFTPA2 and lung disorder.