The function of CST6 (cystatin E/M, Ensembl gene identifier ENSG00000175315) is as follows. High affinity inhibitor for cathepsin L, cathepsin L2 (cathepsin V), and legumain (PubMed:30425301). Involved in the regulation of epidermal cornification, and hair follicle morphogenesis and maintenance (PubMed:30425301). .