MAPT and Parkinson disease: Interestingly, besides the “clinical overlapping”, α-syn has been shown to physically interact with tau (Sengupta et al., 2015; Andersen et al., 2017) or Aβ1–42 (Parnetti et al., 2013; Andersen et al., 2017) and to induce the formation of hybrid oligomers (“heteroaggregates”) in PD patients’ brains.