CASP1 and pemphigus: Numerous animal, cellular, and human studies have demonstrated that Caspase activation is harmful in experimental pemphigus, and pancaspase inhibitors can block or diminish acantholysis and blister formation in pemphigus in vitro and in vivo, respectively.41, 42, 43, 44, 45 Wang et al. used Trypan blue in vivo staining to evaluate cell mortality and found that YVAD-CHO, a Caspase-1 inhibitor, could decrease PV-IG-induced keratinocyte death and tissue acantholysis.46