GZMB and neoplasm: However, the functionality and intratumoral infiltration of CTLs are severely hindered by immunosuppressive and non-immune stromal components that create a non-T cell inflamed TME, characterized by an absence of tumor antigen presentation and sequestered CD8 + T cells around the tumor margin with low expression of cytotoxic markers, such as IFN-γ and granzyme B[37].