PLAU and neoplasm: Immunohistochemistry (IHC) confirmed elevated expression of the cytotoxic effector cytokines (GzmB, IFN-γ, TNF-α) in tumor tissues of uPA–/– mice (Figures 3D, E), whereas ELISA confirmed increased serum levels of these cytokines in uPA–/– tumor-bearing mice (Figure 3F).