Ovarian tissue banking is the process in which one entire ovary (or part of an ovary) is removed surgically, and the outer surface (cortex), which contains the eggs, is frozen in strips for later use. Women who are survivors of some types of cancer can have pieces of the tissue thawed and transplanted back into the body. A number of pregnancies have resulted from using this technique. Transplantation is not always safe following some types of cancer (e.g. leukemia) because of the risk of re-seeding the original cancer. The Oncofertility Consortium® is actively researching new ways to use this tissue. New techniques are still experimental but may be the best option for women who must begin their treatments immediately.