In the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) animal model of PD there is evidence demonstrating the neurotoxic contribution of microglia-produced TNF [127], IL-1β [128], IL-6, and NO [129] to the loss of dopaminergic neurons. The gene discussed is IL1B; the disease is Parkinson disease.