The GM-CSF gene encodes for a cytokine that regulates the production, differentiation, and function of macrophages and granulocytes. The active form of the protein exists as a homodimer in the extracellular space. This gene is located in a cluster of related genes at the chromosome region 5q31, which has been associated with interstitial deletions in the 5q- syndrome and acute myelogenous leukemia. Other genes in the cluster include interleukins 4, 5, and 13. The gene is involved in promoting tissue inflammation. Elevated levels of cytokines, including the one produced by this gene, have been observed in SARS-CoV-2 infected patients with acute respiratory distress syndrome. Mice that lack this gene or its receptor have been shown to develop pulmonary alveolar proteinosis.