MEF2D and Parkinson disease: Indeed, many evidences directly sustain a MEF2D involvement in PD pathogenesis: reduced MEF2D levels were observed in brains of patients, in PD animal models and in response to asyn accumulation and aggregation (Yang et al., 2009; Chu et al., 2011), although unchanged MEF2D expression was observed in lymphomonocytes obtained from PD patients (Sala et al., 2014).