Furthermore, we observed that both CAR-T cells (Figure 1F and Supplementary Figure 3A), as well as B cell leukemia and lymphoma cells, Raji, Nalm-6, and Daudi (Supplementary Figure 3B), expressed 4-1BB ligand, which provided a source of activation signaling to 4-1BB. This evidence concerns the gene TNFRSF9 and lymphoma.