MIF and endometriosis: Moreover, the level of serum MIF differed according to the stage of endometriosis with progressive increase with advancing stage (stage I 1.3 ± 1.03 pg/ml-75 patient, stage II 1.7 ± 1.57 pg/ml − 21 patient, stage III 2.1 ± 1.19 pg/ml – 39 patient, and in stage IV 3.2 ± 2.6 pg/ml – 15 patient) (Table 3).