CDK5 and Parkinson disease: Moreover, in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD, the c-Abl inhibitor imatinib (STI-571) reverses abnormally increased striatal phosphorylation of Tyr15-Cdk5 and Thr75-DARPP-32, as does L-3,4-dihydroxyphenylalanine (L-DOPA; Yamamura et al., 2013).