With this material, we invite you to explore the world of Genethon, a leading laboratory in designing gene therapies for rare diseases. EHC staff attended a three day training there to learn about the concepts behind this novel therapy and how it works. In part II of the video, we talk to Elena Barbon, a PostDoc researcher at Genethon, about the recent advances and challenges of gene therapy for haemophilia and Von Willebrand Disease.