The results of the present study demonstrate that PDIA3 expression is modulated in an age- and pathology-dependent fashion in the limbic brain regions of Non-Tg and 3×Tg-AD mice; moreover, we analyzed for the first time the expression pattern of PDIA3 in a number of brain cell populations derived from 6 month- (the stage of mild pathology) and 18 month-old (the stage of severe pathology) 3×Tg-AD mice. The gene discussed is PDIA3; the disease is Alzheimer disease.