A higher percentage of cytotoxic CD56dimCD16bright cells in the blood of patients with endometriosis before treatment (OR 5.25, DI 0.44; 62.12, p < 0.001) and during treatment (OR 1.92, DI 0.94; 3.93, p = 0.006), as well as the content of CD206+ monocytes during treatment (OR 0.82, DI 0.62; 1.08, p = 0.038), determined the effectiveness of relieving pain symptoms in adolescence after 1 year of treatment of endometriosis with progestogens. This evidence concerns the gene MRC1 and endometriosis.