INS and polycystic ovary syndrome: Moreover, Hu et al. showed a weak PPARγ mRNA expression in granulosa cells of PCOS patients, that varied in relation to the clinical features of the disease and was upregulated following administration of different dosages of insulin and/or rosiglitazone [88]. In vitro experiments run on human ovarian cells demonstrate the negative regulation exerted by TZDs on steroidogenic enzymes 3-β-hydroxysteroid-dehydrogenase (3β-HSD) and aromatase [80, 89, 90].