定常状態
Steady state granulopoiesis is a term used to describe the normal daily production of granulocytes. Granulocytes are short lived cells (their lifespan is between 6 and 8 hours) with a high cell turnover. The number of granulocytes produced every day is between 5 and 10 x 1010. The master regulator of steady state granulopoiesis is C/EBPα. It restricts the cell cycle of immature cells by inhibition of CDK2 and CDK4 and promotes granulocytic differentiation. Steady state production of granulocytes is activated after the engulfment of apoptotic granulocytes by tissue macrophages.