PDIA3 and Alzheimer disease: PDIA3, an ER isomerase expression is altered in 3xTg-AD mice,51 and FKBP9 part of a class of chaperones linked to AD progression,52 has been directly implicated in a prion seeding assay in vitro.113 In addition, TRAM2 is a member of the translocon that is involved in the posttranslational processing of proteins at the ER membrane.114