SFTPA2 and pulmonary fibrosis: Four surfactant-associated genes—surfactant protein A1 (SFTPA1), surfactant protein A2 (SFTPA2), surfactant protein C (SFTPC) and the ATP-binding cassette-type family A member 3 transporter (ABCA3)—are implicated in familial and sporadic pulmonary fibrosis (Table 1) 17, 44.