Our in vivo experiment showed that the peritoneum of all mice contained high levels of the cytokine CSF-1, while the level of the cytokine CSF-1 was significantly higher in the ectopic endometrial tissue of mice with endometriosis than in the eutopic endometrial tissue of mice with endometriosis and the normal endometrium of control mice. Here, CSF1 is linked to endometriosis.