SNCA and Parkinson disease: Despite these partly divergent results, the studies by Luk et al. [55], Masuda-Suzukake et al. [58] and Recasens et al. [75] consistently failed to detect typical PD symptoms (such as tremor, rigor, slowness of movement or postural instability) in wild-type mice after the transmission of α-synuclein inocula.