To understand the mechanisms by which nesfatin-1 exerts its neuroprotective effects, our first step was to examine whether the diminished CSF nesfatin-1 level induced apoptosis in nigral dopaminergic neurons, since cell apoptosis has been repeatedly shown in the literature to be associated with nigral dopaminergic neuron degeneration in postmortem brain tissues from PD patients (Mochizuki et al., 1996; Anglade et al., 1997). Here, NUCB2 is linked to Parkinson disease.