The ESID 2024 programme promises a rich tapestry of insights and discussions, particularly highlighted by its keynote and plenary sessions featuring a diverse array of international speakers. These sessions delve into cutting-edge topics within the realm of immunodeficiency, bringing together experts from around the globe to share their expertise and perspectives. From understanding the intricacies of human thymus to exploring the latest breakthroughs in functional studies, each session offers a unique opportunity to delve into the forefront of research and clinical practice. The keynote sessions promise to be particularly intriguing, setting the tone for an intellectually stimulating conference.