Moreover, in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD, which causes striatal tyrosine hydroxylase depletion and subsequent dopaminergic cell death, the adeno-associated viral type-2 vector containing the complementary DNA for human IL-10, injected intracerebroventricularly before MPTP injection, provided neuroprotective effects by increasing striatal tyrosine hydroxylase [94]. The gene discussed is TH; the disease is Parkinson disease.