Recently, Li et al. (2010) demonstrated that incubation of neonatal mouse ovarian fragments with an inhibitor of the Phosphatase with TENsin homology deleted in chromosome 10 (PTEN) phosphatase and a PI3K activating peptide, increased nuclear exclusion of Foxo3 and propelled large numbers of dormant primordial follicles into becoming FSH-responsive antral follicles. Furthermore, in the nude mice model (mice lacking immune system) they showed that transplanted human ovarian fragments containing mainly primordial follicles from surgical specimens, treated by the same incubation, also underwent activation of dormant follicles to derive preovulatory follicles containing mature oocytes.