PADI4 and peripheral arterial disease: Due to the inherent ability of citrullinated proteins to cause autoimmunity [16,17,18,19,20,21,22] and our previous finding that PAD4 is the primary retinal PAD in mouse [23], we tested the Ter349Glu retina for changes in PAD4 expression and citrullination compared with WT retina at 10 to 12 weeks of age (Figure 7).