Comparison of expression of apoptosis-related genes to GAPDH in non-vitrified and vitrified human ovarian tissue. The ratio of genes expression of Bax, Fas, FasL, p53, caspase 3, and caspase 8 to GAPDH(A) and the ratio of Bcl-2, BIRC5 to GAPDH (B) using real-time RT-PCR in non-vitrified and vitrified groups. *Significant differences between groups (P<0.05).