CD8A and neoplasm: To evaluate the impact of co-stimulatory 4–1BBL on CD8POS T cells during an rIL-12-mediated anti-tumor response, mice were systemically depleted of CD8POS T cells with systemic anti-CD8 mAb to avoid CD8POS T cell accumulation at the CT-2A-FLuc-Tnfsf9 tumor site (Figure 6I).