Cathepsin E is an enzyme (EC 3.4.23.34) that in humans is encoded by the CTSE gene.[5][6][7] The enzyme is also known as slow-moving proteinase, erythrocyte membrane aspartic proteinase, SMP, EMAP, non-pepsin proteinase, cathepsin D-like acid proteinase, cathepsin E-like acid proteinase, cathepsin D-type proteinase) is an enzyme.[8][9][10][11]