In addition, landmark reports showed that in a rodent model of PD, striatal dopamine deficiency had no effect on phosphorylation of Thr34-DARPP-32, but significantly increased that of Thr75-DARPP-32 (Brown et al., 2005; Santini et al., 2007), as we observed here in the MPTP mice. The gene discussed is PPP1R1B; the disease is Parkinson disease.