PRF1 and neoplasm: As depicted in Figure 4C, perforin and TNFα staining levels were significantly greater in all examined CD8+ T cell populations when RMA target cells were present, and while perforin and TNFα levels were similar for spleen CD8+ T cells from PBS and hAAT-treated mice (solid bars), tumor CD8+ T cells from hAAT-treated mice expressed significantly greater perforin and TNFα levels than either spleen or tumor CD8+ T cells from PBS-treated cells (empty bars).