The major pathophysiological factors of CRS include elevated central venous and abdominal pressures, decreased cardiac output and cardiac index, neurohormonal dysregulation (renin-angiotensin-aldosterone system (RAAS) activation, sympathetic nervous system activation, and vasopressin), oxidative stress, inflammatory mediators, renal failure-related disturbances, and iatrogenic factors [10]. The gene discussed is REN; the disease is kidney failure.