CTSG and type 1 diabetes mellitus: For instance, it was demonstrated that CatG activity, analyzed by MARS116 in a Western blot-based assay, was increased in PBMCs from T1D patients in comparison to PBMCs isolated from healthy donors, and CatG was responsible for generating insulin-derived T cell epitopes supporting the autoimmune event by activating autoreactive T cells (diabetogenic T cells) (Zou et al., 2011).