In humans it is encoded by the CTSE gene located at 1q32 on chromosome 1.[12][13][3][14] It is an intracellular non-lysosomal glycoprotein that is mainly found in the skin and in immune cells.[15] The protein is an aspartyl protease that functions as a disulfide-linked homodimer, and has an oligosaccharide chain of the high-mannose type.[16] It is a member of the peptidase A1 family, and therefore observes specificity similar to that of Pepsin A and Cathepsin D. Cathepsin E is an intracellular enzyme and does not appear to be involved in dietary protein digestion.