Expression levels and localization of transcription factors cAMP response element binding protein (CREB(1) and CREB(2)) and c-Fos, as well as levels of up-stream mitogen-activated protein kinases/extracellular signal-regulated kinases (ERK-1 and ERK-2) and p38 kinase, were examined in the brains (frontal cortex) of eleven cases with Creutzfeldt-Jakob disease (CJD) and five age-matched controls.