CSF2 and neoplasm: Previous studies linking eosinophil function and tumor biology have indicated that eosinophil production of eosinophil peroxidase (EPO) and reactive oxygen species (ROS) may amplify oxidative damage and tumorigenesis in the lung [114], possibly via induced activation by the cytokine, GM-CSF, which has been shown in vitro to elicit these responses in human eosinophils [112].