FGF5 and neoplasm: Immunohistochemical (IHC) staining of formalin-fixed paraffin embedded (FFPE) tumor sections from the excised xenotransplanted tumors confirmed overexpression of FGF5 on the protein level in VM21-FGF5 compared to VM21-GFP cells and demonstrated the specificity of the antibody on paraffin sections (Figure 5B).