Oksjoki et al. [50] found that proα1(IV) collagen and TIMP-3 transcripts were significantly lower in PCOS compared to normal follicular phase ovaries, which accompanied altered immunohistochemical staining of MMP-9 and TIMP4, suggesting the involvement of the basement membrane in the pathogenesis of PCOS. The gene discussed is MMP9; the disease is polycystic ovary syndrome.