In line with this, previous studies reported that inhibiting PTPs protected dopaminergic neurons from PD toxins by activating ERK1/2 via increasing BDNF signaling (Lu et al., 2002), and that phosphorylation of ERK1/2 and CREB was decreased in sporadic PD samples (Kurup et al., 2015). This evidence concerns the gene CREB1 and Parkinson disease.