These include mouse models of chronic prostatic inflammation induced by immunization with prostate antigen (PAg) [13], rat models with chronic inflammation induced by combined testosterone and E2 treatment [14], or a transgenic mouse model with aromatase (ARO+) over-expression leading to chronic prostatitis and prostate pre-malignancy with increased mast cell infiltration [15]. The gene discussed is CYP19A1; the disease is chronic prostatitis.