Proposed model for IL-7Rα trafficking. At the steady state, IL-7Rα is slowly internalized via clathrin-coated pits and recycled back to the cell surface, with a pool of receptor being degraded and replaced by newly synthesized IL-7Rα (not shown). On IL-7 stimulation, the balance is rapidly shifted toward receptor endocytosis and subsequent degradation. JAK3 activation, which appears to rely on IL-7Rα being internalized, is critical for triggering receptor degradation.