As with José Arcadio Buendía, megakaryocytes traverse the endosteal jungle of the bone marrow to rest adjacent the rivers of the vascular niche (A, Steady-state). Higher vascular concentrations of SDF-1 direct megakaryocyte chemotaxis to the blood vessel and are inverted by radiation damage (B, Day 2). Megakaryocyte migration to sinusoidal blood vessels accounts for vascular platelet release (C, Day 3). Professional illustration by Paulette Dennis.