WNT1 and Parkinson disease: The majority of papers published on this issue aim to demonstrate as the pharmacological activation of β-catenin signaling, by Wnt1 or Wnt1-like agonists (Wei et al., 2013) or by GSK inhibitors (L’Episcopo et al., 2011a; Zhou et al., 2016), has neuroprotective capacity against DA neuron-specific toxins or is able to prevent loss of mDA neurons in the substantia nigra and to ameliorate motor symptoms in animal models of PD (L’Episcopo et al., 2011a).