Mice with inactivated aromatase genes, and hence the inability to synthesise oestrogen, developed signs of autoimmunity which resemble Sjogren’s syndrome (17) Another study conducted on mice suggests that transgenic (Tg) expression of the retinoblastoma-associated protein 48 (RbAp48) induces tissue specific apoptosis in exocrine glands; dependant on the level of estrogen defiency (18). The gene discussed is CYP19A1; the disease is Sjogren syndrome.