This guide highlights the revolutionary new treatment options offered by CAR-T cell therapy, which may bring hope to many people with autoimmune diseases. It begins with the basics of CAR-T cell therapy, explaining how these innovative immune cells work and why they are considered a breakthrough in medicine. It then provides an overview of autoimmune diseases, from well-known conditions such as multiple sclerosis and arthritis to less common but equally distressing conditions. A central part of the book is devoted to the specific application of CAR-T cell therapy in autoimmune diseases. It explains how this form of therapy, which was originally developed for the treatment of cancer, is now also being used to treat autoimmune diseases and what successes have already been achieved. It also presents the current state of research and the results of clinical studies that show how far science has already come in this area. The book also addresses the opportunities and challenges of CAR-T cell therapy. While this form of therapy offers great potential, there are still questions that need to be answered in order to further improve its application and make it safer. Finally, we will take a look into the future: What developments can be expected and how could CAR-T cell therapy positively change the lives of millions of people in the coming years? This book is aimed at anyone interested in new medical developments, but especially those affected and their relatives who are looking for information that is both comprehensible and detailed.