Cathepsin E is an intracellular aspartic protease of the endolysosomal pathway. It has been implicated in several physiological and pathological processes however, its exact functional role is yet to be elucidated. The present review gives an account of the Major physiological functions that are associated to cathepsin E by various research groups and highlights the conditions developed in cathepsin E deficiency or the conditions where overexpression of cathepsin E is observed. (C) 2008 Elsevier Inc. All rights reserved.