Aspartic Peptidase， Retroviral-Like 1（ASPRV1) is a protein which contains one peptidase A2 domain. ASPRV1 undergoes autocleavage which is essential for activation of the protein. ASPRV1 is expressed mostly in the granular layer of the epidermis and inner root sheath of hair follicles and localized to membrane region. In the psoriatic skin， ASPRV1 is expressed throughout the stratum corneum. In the ulcerated skin， ASPRV1 is expressed in the stratum granulosum of intact epidermis； however it is virtually nonexistent from ulcerated regions. In addition， ASPRV1 is expressed in differentiated areas of squamous cell carcinomas but not in the undifferentiated tumors.
