PTGS2 and cerebral cavernous malformation: Furthermore, the up-regulation of ROS led to increased expression and activation of the redox-sensitive transcription factor c-Jun, as well as induction of its downstream target cyclooxygenase-2 (COX-2)18, suggesting that KRIT1 can limit both pro-oxidant and pro-inflammatory pathways that in turn may influence CCM disease pathogenesis.