The critical involvement of immune cells in the development of hypertension was recognized through pioneering research by Guzik and colleagues back in the mid-2000s, who demonstrated that mice lacking T and B cells, particularly Rag1−/− mice, were particularly protected from hypertension caused by activation of angiotensin II (Ang-II) and deoxycorticosterone acetate. Here, AGT is linked to hypertensive disorder.