The University of Liège Medical School and GIGA Institute are extremely proud and honored to receive Pr Alain FISCHER from the prestigious Collège de France in the framework of the Princess Lilian Professorship 2019. Alain Fischer is one of the most prominent immunologists in the world and a leader in the field of hereditary immune deficiencies (HID) and their treatment by gene therapy. His major scientific achievements are summarized here.