The harvested ovarian cortex will be cut: one half will be frozen according to our routine protocol [Schubert et al. 2005] and the other half will be contaminated with tumor cells lines. Then, detection of the specific transcript will be done by RT-PCR in fresh tissue and after freeze/thaw. Total RNA will be extracted with the TRI-reagent and qRT-PCR will be performed using the "TaqMan" technology.