The enzyme was also expressed at high levels in the activated microglia of the hippocampal CA1 region and in degenerating neurons for a week after transient forebrain ischemia.[2] Cathepsin E has a possible role in the development of well differentiated adenocarcinoma from intestinal metaplasia.[3] The enzyme also plays a part in association with dendritic cells where it generates the CD4 repertoire in response to self and foreign proteins.[20]