E-learning Module 4 on von Willebrand disease with Luciano Baronciani and Omid Seidizadeh focuses on the diagnosis of this complex bleeding disorder. The module provides an update on the current literature regarding von Willebrand disease and covers various aspects of diagnosis, including laboratory testing, and differential diagnosis. Through this module, learners will gain a better understanding of the challenges involved in diagnosing von Willebrand disease and the importance of accurate diagnosis for the effective management of patients with this disorder.