Autologous transplantation is a medical procedure where a patient's own cells or tissues are collected, processed, and then reintroduced into their body. This technique is commonly used in treatments for certain types of cancer, such as multiple myeloma and lymphoma, where healthy stem cells are harvested from the patient before undergoing chemotherapy or radiation. After the treatment, the harvested cells are returned to the patient to help restore their immune system and promote recovery. This method reduces the risk of rejection and complications associated with using donor cells, making it a safer option for many patients undergoing intensive therapies.