PRF1 and dermatomyositis: A major function of CD8 T cells is to kill target cells via their cytotoxic molecules such as Perforin and Granzymes.[11] In this study, we performed a comprehensive analysis of the expression of main cytotoxic molecules in CD4 and CD8 T cells from active MDA5+DM patients and healthy donors (HDs), with the aim of identifying disease-associated cytotoxic T cell pattern and its potential clinical relevance in MDA5+DM.