CARD9 and autoimmune bullous skin disease: Moreover, numerous studies have been conducted to examine proteins (including PLCγ2 and CARD9) in signal transduction following Fcγ-receptor activation in <i>in vitro</i> and <i>in vivo</i> experimental pemphigoid models, and an increasing number of case studies involving JAK inhibitors report the successful application of these drugs in various pemphigoid diseases.