H2AX and endometriosis: Post-treatment γ-H2AX expression levels in Ishikawa cells and endometrial stromal cells of patients with endometriosis patients were significantly elevated, compared with pretreatment levels [relative γ-H2AX expression/GAPDH: 0.88 ± 0.25 vs. 5.03 ± 1.02 (p = 0.049) and 1.00 ± 0.15 vs. 2.02 ± 0.26 (p = 0.016), respectively].