Compared to controls, patients with endometriosis had lower serum E-cadherin: 107.6 ± 31.9 vs. 137.9 ± 94.5 ng/5 μg protein (p < 0.05); higher N-cadherin: 525.3 ± 214.8 vs. 286 ± 118.6 (p < 0.01), and higher HIF-1α: 540 ± 222 vs. 272 ± 84 (p < 0.001). This evidence concerns the gene CDH2 and endometriosis.