The pathogenesis of thrombosis in the MPNs. MPNs and the CHIP from which they originate are both risk factors for venous thrombosis and atherosclerosis. Atherosclerosis, in turn, is the major substrate for arterial thrombosis. MPNs and systemic inflammation promote each other bidirectionally. Systemic inflammation itself, independent of MPNs, provokes venous thrombosis, atherosclerosis, and arterial thrombosis. Like the MPNs, other cancers and systemic inflammation promote each other bidirectionally. CHIP is also associated with other cancers. Professional illustration by Patrick Lane, ScEYEnce Studios.