SLC2A4 and polycystic ovary syndrome: It has been reported that metformin decreases local androgen synthesis in human ovarian cells [79,80], increases GLUT4 expression in endometrial cells from PCOS women with hyperinsulinemia [81], inhibits cell proliferation [36,37], and induces cell cycle arrest and apoptosis [35] in type I EC cells, all of which have been proposed to occur through activation of AMPK signaling [35-37,39,81,82].