Caspase 14 (CASP14) is an enzyme that belongs to the peptidase C14A family. The Caspase 14 protein is complexed of unprocessed caspase-14 and processed 19 kDa (p19) and 10 kDa (p10) subunits. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes, which undergo proteolytic processing at conserved aspartic residues to produce two subunits, large and small, that dimerize to form the active enzyme. CASP14 has been shown to be processed and activated by Caspase 8 and Caspase 10 in vitro, and by anti-Fas agonist antibody or TNF-related apoptosis inducing ligand in vivo. The expression and processing of this caspase may be involved in keratinocyte terminal differentiation, which is important for the formation of the skin barrier. It is believed to be a non-apoptotic caspase which is involved in epidermal differentiation, keratinocyte differentiation and cornification. CASP14 probably regulates maturation of the epidermis by proteolytically processing filaggrin.