The 51th Congress of the “Societe Internationale d’Oncologie Pediatrique” (SIOP) will be held from October 23-26, 2019, in Lyon, France. SIOP aims for a world, where no child should die of cancer. SIOP brings together all the caregivers - such as nurses, surgeons, and paediatric and radiation oncologists - involved in the care of children and teenagers with cancer as well as their parents from all around the world. Every year SIOP meets to share results, experience, difficulties, progress and new tools, enriching each other. The SIOP congress is a unique and magical event where each caregiver can add their personal touch to improve knowledge or meet their seniors to learn more. SIOP also aims to put all countries in the world under the same umbrella for the patients to be able to receive equal levels of diagnosis, treatment and care. We believe we must work together to solve many problems and challenge together for the future. Join SIOP and its partners - Childhood Cancer International (CCI), The International Society of Paediatric Surgical Oncology (IPSO) and the Paediatric Radiation Oncology Society (PROS) - to experience 4 outstanding days full of cutting-edge science, engaging debates and networking with world renowned experts. We look forward to welcoming you to Lyon!