Histological analysis of PTTG transgenic uterus. The uteri from transgenic mice (a and b) had large cysts and multiple small fluid-filled glandular cysts compared to non transgenic mice (e and f). Scar formation and hemosiderin laden granules (asterisk in f) were evident in wild-type but absent in transgenic uterus. Both wild-type and transgenic uteri were PCNA positive; PCNA staining in transgenic uteri of transgenic animals was much darker and homogeneous compared to non-transgenic animals, suggesting the presence of highly proliferative cells both in luminal and glandular epithelium. Negative control sections in which primary antibody were omitted did not display any PCNA staining (h). The figure was reproduced with permission from J Endocrinology .