In the cardiovascular system AQP1, AQP4, AQP7, and AQP9 are expressed in endothelial cells, vascular smooth muscle cells, and cardiac tissue which all play a vital role in the development and progression of pathologies such congestive heart failure, ischemia, hypertension, and angiogenesis [119]. The gene discussed is AQP9; the disease is congestive heart failure.