Mean numbers of tissue S100A12+ cells were significantly higher in dogs with severe prostatitis (median: 9 cells/0.01 mm2) compared to dogs with prostate neoplasia (median: 1 cell/0.01 mm2; P = 0.0458), BPH (median: 1 cell/0.01 mm2; P = 0.0163), or controls (median: 0 cells/0.01 mm2; P = 0.0089). The gene discussed is S100A12; the disease is benign prostatic hyperplasia.