We also revealed that OPN and MMP2 mRNA levels were increased in endometriotic lesions in both endometriosis models in comparison with normal tissue however the expression of OPN and MMPs gene was higher in model B compared to the model A. Our findings on OPN gene expression are in agreement with other reports which have demonstrated an increase in OPN expression in a rat model of endometriosis in comparison to normal rats endometrial tissue and in patients with endometriosis in comparison with control subjects (28, 51-53). The gene discussed is SPP1; the disease is endometriosis.