Form and Function (IMAGE) University of Pennsylvania School of Medicine Caption This is the structure of the components of the antigen-antibody complex at the root of HIT. Credit Perelman School of Medicine, University of Pennsylvania; Nature Communications Usage Restrictions None License Licensed content 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.