SERPINE1 and polycystic ovary syndrome: A downward trend was noted from antral to preovulatory follicles in control ovaries (% of follicular staining 14.1 ± 11.0 in antral versus 0.24 in pre-ovulatory follicles), however an increase in PAI-1 concentration in these same follicles was observed in PCOS ovaries (% of follicular staining 14.6 ± 14.6 in antral versus 23.3 ± 12.9 in preovulatory follicles) (Table 3 and Fig. 5a), though a statistical analysis could not be completed due to the low numbers of preovulatory follicles.