PRDM1 and type 1 diabetes mellitus: Our results illustrated that these Blimp-1 deficiency–modulated and IL-21–dependent inflammatory diseases and disorders include abnormal morphology of the immune system, inflammation of the gastrointestinal tract, inflammation of the central nervous system, and insulin-dependent diabetes mellitus (Figure 3I), supporting that Blimp-1 deficiency is correlated to IL-21–based autoimmune diseases.