To examine the location of insulin-like growth factor II (IGF2) in human testicular tissues, we performed immunohistochemistry staining to detect the IGF2 expression. Tissues were cut into sections for immunoperoxidase staining after being treated with 4% PFA and paraffin wax. After the specific treatment with standard-procedure immunohistochemistry staining as described as Lian et al. [10 (link)], sections were incubated with IGF2 antibody (Abcam) overnight at 4°C and biotinylated secondary antibody (Abcam) for 2 h at room temperature.