When estrogen is not balanced with progesterone, the estradiol will stimulate the lining of the uterus to grow uncontrollably. The abnormal growth of part of the uterus tissue tends to develop fibroids. Furthermore, when menstrual blood flows backwards from the uterus into the fallopian tubes and spreads into pelvic tissues, part of the uterus lining can also travel with the blood and implant outside the uterus causing endometriosis (Khaleque Khan et al. 2005). Women with endometriosis tend to have higher than normal levels of hepatocyte growth factor and higher growth factor level may facilitate the endometrial tissue growing outside the uterus. The estrogen dominance condition can change the gene expression.