CSF2 and Parkinson disease: Our works demonstrated that granulocyte–macrophage colony stimulating factor (GM-CSF, sargramostim, Leukine®) increases Treg numbers and function, protects dopaminergic neurons in PD animal models [178, 274], and improves motor function as determined by UPDRS and magnetoencephalography (MEG)-recorded cortical output in PD patients [180, 181, 275].