RXFP1 and Hypertension: Here, we discuss angiotensin II receptors (AT1R and AT2R), Mas receptor (MasR), Mas-related G-protein-coupled receptor member D (MrgD), relaxin family receptor 1 (RXFP1), adenosine receptors (A1, A2A, A2B, and A3), purinergic P2Y receptors, and endothelin receptors (ETA and ETB) because they play important roles in the regulation of hypertension and kidney function (Figure 1).