Meanwhile, in a PD rat model induced by injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), nitrated alpha-synuclein (N-α-synuclein) was detected to break immunological tolerance and activate T cells into Th1 and Th17 subsets of T helper cells (56–58). Here, SNCA is linked to Parkinson disease.