Autologous transplantation of frozen-thawed human ovarian tissue is a groundbreaking procedure that helps preserve fertility in girls and women undergoing treatments that can harm their ovaries. By freezing and storing a piece of ovarian tissue before treatment, doctors can later implant it back into the patient to restore hormone function and fertility. This method is especially important for young girls and women who need to start treatment quickly for diseases like cancer. The procedure has been successful in restoring reproductive potential in patients after they have been cured of their illness.