NCAM1 and Parkinson disease: The immune infiltration analysis revealed eleven differential infiltrative immune cell types in the substantia nigra between PD and control samples: neutrophils, mast cells, Tfh cells, plasmacytoid DCs, MDSCs, NK T cells, Th1 cells, effector memory CD8 T cells, immature B cells, immature DCs, and CD56 bright NK cells.