This session will review the pathophysiology of VITT and the key role of PF4-dependent neoantigens, novel assays of platelet activation that were recently developed to confirm the diagnosis of VITT and the unique factors of the cerebral venous sinuses that promote acute thrombosis in VITT . This session is relevant to three areas of the ASH research agenda: COVID-19, infectious diseases and hematology and thrombosis and vascular biology. Understanding and managing the “new” condition of VITT was a major focus for scientists and coagulation specialists over the last 12 months, and the insights gained from these efforts will guide management of other immune-mediated procoagulant syndromes.