In the analysis using the stromal-dominant BPH model rat which has the both epithelial and stromal proliferation with time, complement components including C1q, C3, MBL, Factor B, and C5b-9 were highly expressed in rat BPH tissues compared to normal prostate tissues, and these expressions were increased time-dependently [93]. The gene discussed is C3; the disease is benign prostatic hyperplasia.