Platelet factor 4 (IMAGE) University of North Carolina Health Care Caption The red region on the platelet factor 4 (PF4) molecule represents the region recognized by VITT-like antibodies obtained from patient 2 (adult). Credit Mercy Daka (co-author) and Dr. Ishac Nazy (co-author) Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.