Also, some studies have reported an increase in brain-derived neurotrophic factors (BDNFs) and glia cell line-derived neurotrophic factor (GDNF), neurotrophins known to regulate survival and activity of dopaminergic neurons, following short bouts of aerobic exercise in PD patients (Frazzitta et al., 2014; Zoladz et al., 2014; Marusiak et al., 2015). The gene discussed is BDNF; the disease is Parkinson disease.