CD8A and neoplasm: Further, CD8+ T cells from mice receiving PaCa-EV-treated macrophages also showed significantly decreased numbers of IFNγ+CD8+ T cells in the blood (Fig. 2n), with a similar representation in the spleen (Fig. 2o) as compared to mice that received non-tumorigenic-EV-treated and/or untreated macrophages, indicating that PaCa-EV-treated macrophages adversely impact the anti-tumor activity of CD8+ T cells.