Renin is an enzyme belonging to the aspartyl protease family, specifically responsible for cleaving angiotensinogen to generate angiotensin I, triggering the renin-angiotensin-aldosterone system to regulate blood pressure and fluid balance. This enzyme is primarily synthesized and secreted in the juxtaglomerular cells of the kidneys. The gene expression of renin is regulated by various factors in the renin-angiotensin system, such as increased renin release when blood pressure drops or sodium ion concentration decreases. Specific expression and activity regulation are crucial for maintaining blood pressure stability. Mutations or abnormal expression of the renin gene are associated with health issues such as hypertension and cardiovascular diseases, and its inhibitors are commonly used to treat hypertension and heart failure.