Accumulation of ER chaperons was found in LBs (Conn et al., 2004) while increased PERK/p-eIF2α signaling was demonstrated in dopaminergic neurons of the substantia nigra in post-mortem tissue from PD cases, confirming that PD pathology is intimately associated with activation of ER stress in vivo (Hoozemans et al., 2007). Here, EIF2A is linked to Parkinson disease.