Experimental studies in non-obese diabetic (NOD) mice and PAD4-knockout NOD (PAD4−/−NOD) mice found that PAD4 deficiency resulted in a significant reduction in the number of intestinal M1 macrophages and MET formation, leading to suppressed migration of gut-derived T cells and a delay in T1D progression [45]. This evidence concerns the gene PADI4 and type 1 diabetes mellitus.