CD3+CD4+ cells and CD3+CD8+ cells were first gated, and the results indicated that the percentages of IFN-γ-expressed CD4+ and CD8+ T cells in the infertile patients with PCOS were significantly lower than those in the infertile patients with normal ovulation (23.6% ± 3.4% vs. 16.9% ± 2.6%, P < 0.05; 31.8% ± 2.5% vs. 22.5% ± 2.2%, P < 0.01). This evidence concerns the gene CD4 and polycystic ovary syndrome.