CD19 and neoplasm: To explore the in vivo anti-tumor activity of CAR/CCR T cells in comparison with CAR (2nd Gen) constructs, we intravenously injected 5 × 104 CD19+CD80highCD86high cells of the Burkitt B cell lymphoma cell line Raji on day −4 into Rag2– γc– immunocompromised mice (Figure 3A).