Our results showing significant increase in ARTS-positive -apoptotic cells seen mainly within 24 hours following 6-OHDA treatment, are consistent with the caspase-3 cleavage data in MPTP mice model for PD, which reveal that caspase-3 cleavage peaks early, at days 1 and 2 after the end of MPTP intoxication in these mice [58]. This evidence concerns the gene CASP3 and Parkinson disease.