Kidneys are commonly known to be responsible for the excretion of water-soluble waste products. Besides that essential function the kidneys work as control centers for a variety of essential body functions, which explains the multimorbidity of patients suffering from kidney disease. These homeostatic functions include maintenance of blood oxygen transport, blood pressure, acid-base balance, mineral and electrolyte balance and others. Since our knowledge of the mechanisms underlying normal and disturbed homeostatic kidney functions is still steadily growing Pflügers Archiv will devote a Special Issue to this further developing and clinically highly relevant field, both from a basic science and from a translational perspective.