Immunohistochemistry (IHC) is a well-established method for identifying both cellular and tissue antigens by means of specific antigen-antibody reactions [1]. This method is a unique analytical tool combining molecular detection with morphological features and can be used on formalin-fixed and paraffin-embedded sections, frozen sections, conventional cytological smears, and other cytological preparations (e.g. isolated circulating tumor cells) [2]. The use of IHC in cancer research has expanded to involve diagnostic classification, anti-tumor drug development, disease prognosis, therapy selection, prediction to response and follow-up, contributing significantly to personalized medicine.