Furthermore, the negative correlations between IGF‐1 on the one hand and prostate gland volume (all dogs: p < 0.05, RR CPSEn with clinical signs p < 0.01, RR CPSEn&CPSEi with clinical signs p = 0.05) and the serum CPSE concentration (p < 0.05) on the other hand (Table 1) contradict a stimulating effect of IGF‐1 on BPH development. The gene discussed is IGF1; the disease is benign prostatic hyperplasia.