We found that whereas DAP12 and CD11b partially contribute to microglia-induced DN cell death in vitro, mice deficient for either of these factors develop similar neuropathological alterations to their wild-type (WT) counterparts in two different 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse models of PD. This evidence concerns the gene ITGAM and Parkinson disease.