Rhys Evans, the first child in the UK to receive pioneering gene therapy for Severe Combined Immunodeficiency (SCID), has returned to Great Ormond Street Hospital to thank the medical team that saved his life 25 years ago.Born without an immune system, Rhys was kept in a sterile 'bubble' environment from infancy to prevent infections.His treatment in 2001 involved experimental gene therapy, which enabled his body to develop its own immune system.Now 25, Rhys works in a coffee shop and at Butlins, describing himself as '95 per cent normal' despite still requiring antibiotics.The hospital, now a global leader in gene therapy, has treated over 135 children with rare conditions using this technology.Rhys's story highlights the transformative impact of medical innovation, offering hope to families facing similar challenges.His visit marks both a personal milestone and a testament to the advancements in treating immunodeficiency disorders.