This is consistent with the above data, ERK5 depletion (Figure S18C, Supporting Information) in CD19‐CAR‐T cells did not influence CAR‐T cell proliferation (Figure S18D, Supporting Information), but enhanced cytotoxicity in Raji Burkitt lymphoma cells at low effector to target ratios (Figure S18E, Supporting Information), and increased cytokine release (Figure S18F,G, Supporting Information). This evidence concerns the gene CD19 and Burkitt lymphoma.