SHBG and endometriosis: The level of bioactive androgens/estrogens (in the free state) in the organism largely depends on sex hormone-binding globulin (SHBG), which binds/transports a significant portion of the androgens/estrogens of the body and, due to this, changes the amount of these hormones in a free state (bioactive), which may be important in the development of endometriosis.