One of the two technicians who received the highest dose of radiation was treated with PBSCT in an attempt to restore his destroyed immune system. Cells from the patient's sister's bone marrow were administered, and in the following weeks successfully began dividing and differentiating into leukocytes, but several weeks later, the cells were found to have been mutated by the radiation still present within the patient's body, and were observed carrying out autoimmune responses.[10] Later studies on the incident and subsequent use of PBSCT found that the transplant had also induced neoendothelialization of the aortic endothelium.[11]