This goal was achieved through the recognition of the concentration value of BMP-2 and BMP-7 bone morphogenetic proteins and their receptors, type-IALK-1 and type-IIBMPR2, in the peritoneal fluid of women with endometriosis, as well as the determination of whether the tested women showed any correlation between the concentration of the examined parameters and the stage of the disease. Here, BMP2 is linked to endometriosis.