Granulocyte macrophage colony stimulating factor (GM-CSF) is a cytokine that regulates the growth of white blood cells. GM-CSF stimulates stem cells to produce granulocytes (neutrophils, eosinophils, and basophils) and monocytes. In addition, it also has activity on hematopoietic and non hematopoietic lineage cells. GM-CSF is used as a drug to stimulate the production of white blood cells and prevent neutropenia caused by chemotherapy. Recently, clinical trials are underway to evaluate the efficacy of GM-CSF as a potential vaccine adjuvant in HIV infected patients. Related studies have reported that some cancer patients (including lung cancer and acute myeloid leukemia) have high levels of GM-CSF in their serum, as well as in peripheral blood and scale extracts from patients with bronchial asthma.