Serial cytokine assessment of 43 cytokines was performed in 51 patients treated with CTL019. Cytokine profiles were compared in patients who developed severe CRS with patients who did not. Figure 1 depicts peak values of cytokines over the first month. (A). 24 cytokines, including IFNγ, IL6, IL8, sIL2Rα, sgp130, sIL6R, MCP1, MIP1α, and GM-CSF were highly associated with CRS4-5 compared to CRS0-3, significant by Holm’s adjusted p-value. (B). The 19 cytokines that were not statistically different by CRS severity based on Holm’s adjusted p-value.