NOS2 and Parkinson disease: In addition, a number of PD associated genes (Th; tyrosine hydroxylase, Nd4; NADH dehydrogenase, subunit 4, Sncb; β-synuclein, Uchl1; ubiquitin carboxyl-terminal esterase L1, Hsp70; heat shock protein 70, Park2; E3 ubiquitin protein ligase, NFkB; nuclear factor kB and iNOS; inducible nitric oxide synthase) are found to be altered at various time-points during the course of MPTP lesioning10, 11.