This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Uterine fibroids (leiomyomata) are benign tumors of the uterine muscle or myometrium that affect 25-40% of women of reproductive age. Despite the high prevalence of fibroids in reproductive age women, there are few animal models for fibroid disease. To fill this gap we created a human xenograft model for preclinical studies of human fibroids. For this model, fibroids are collected from women undergoing hysterectomy and transplanted into immunodeficient SCID mice for further study. Specific Aim 1 in this study was to assess the morphology and hormone responsiveness of human uterine fibroid and myometrial grafts in these mice. Specific Aim 2 was to test the effects of novel anti-fibroid therapies including androgens and androgen antagonists on growth of fibroid and myometrial grafts in these mice.