Spermatogonial stem cell (SSC) transplantation is an experimental technology which has the potential to be used in the clinic to preserve and restore fertility of prepubertal boys who might otherwise become sterile as a result of another treatment or disease (e.g., chemotherapy for cancer). Prior to a potentially sterilizing treatment in a prepubertal boy, surgeons would biopsy the patient's testis to obtain SSCs (poised to initiate spermatogenesis at puberty), which would subsequently be cryopreserved. Later, after cure of the underlying disease, the cryopreserved SSC could be reintroduced into the testes where they would regenerate spermatogenesis. This approach has the potential to preserve fertility for patients who currently have no other options. Click on the image above to see a cartoon depicting this hypothetical process in the clinic. We are actively studying this approach to preserve and later restore the fertility of prepubertal patients. In addition, we are exploring other non-invasive approaches to prospectively prevent the loss of fertility in boys treated for cancer.