Cryopreservation of ovarian tissue restores fertility, as is already widely known in the scientific world. However, there are no published articles addressing its influence on bone metabolism despite the increase in technologies that increase the survival of cancer patients. This book aims to show that care for morbidities related to the treatment of cancer patients opens up a new paradigm for science: autotransplantation of ovarian tissue after vitrification and reimplantation alters estradiol levels and has a positive bone effect. This new frontier opens up new knowledge and future clinical applications for patients undergoing treatment for cancer and other diseases that lead to ovarian failure and infertility.