Figure 3. IGFBP7 protein expression of human seminal plasma and mice testis. (A) ELISA was applied to detect the expression of IGFBP7 in human seminal plasma. (B) Immunofluorescence showed the localization of IGFBP7 protein in the interstitial compartment of older mice. Scale bar: 250 μm (C) Western blot was applied to detect the expression of IGFBP7 and the senescence marker P21 in testis of mice. Data depict the mean ± SD; *P < 0.05. **P < 0.01.