Although these mice (ovariectomised, athymic, and immunosuppressed nude mice) have no significant peripheral estrogen production capability and no adrenal androgen production, AI efficacy is assessed after inoculation with human breast carcinoma cells transfected with the human aromatase gene (MCF-7arom cells) (Brodie et al, 2005). Here, CYP19A1 is linked to breast carcinoma.