CYP19A1 and endometriosis: It is known from the literature that specific characteristics of the hormone profile of women with endometriosis are: decreased frequencies/amplitudes of GnRH and LH pulses, resulting reduced LH, increased FSH, decreased LH/FSH ratio, increased SHBG, reduced serum/follicular testosterone, high estradiol concentration in lesions (local) and normal or low level of serum estradiol, increased estradiol/testosterone ratio, change of aromatase expression, etc. [4,7,27].