Surfactant protein A (SFTPA1), a member of the collagenous lectin (collectin) family, was first described as a major constituent of lung surfactant but has recently also been found in the female genital tract. Various microorganisms colonize this area and may cause intrauterine infection or trigger preterm labor. The human SFTPA1 and SFTPA2 genes encode SP-A1 and SP-2 proteins, and each gene has been identified with numerous genetic variants. SP-A1 and SP-A2 differentially enhance bacterial phagocytosis. Sex differences have been observed in pulmonary disease and survival of wild type and SP-A knockout (KO) mice. SP-A interacts and regulates many of the functions of alveolar macrophages (AM). It is shown that SP-A variants differ in their ability to regulate the AM miRNome in response to oxidative stress (OxS).