DDIT3 and Parkinson disease: Additionally, in in vitro and in vivo models of neurotoxin-induced parkinsonism, in which neurotoxins such as 6-hydroxy-dopamine (6-OHDA) and MPTP are typically administered, the genetic ablation of Ddit3 (CHOP) [166] and overexpression of XBP1s [167,168] protect neurons from neurotoxin-induced cell death.