A gene microanalysis by Savaris et al. reported that progesterone-regulated genes, including mitogen-inducible gene 6 (MIG6), leukemia inhibitory factor (LIF), GRB2-associated binding protein 1 (GAB1), S100P and claudin-4, were significantly lower in the endometrium of women with PCOS, whereas cell proliferation genes, such as Anillin and cyclin B1, were up-regulated. Here, GAB1 is linked to polycystic ovary syndrome.