Hay et al. [18] identified biomarkers of severe CRS in 133 adult patients who received CD19 CAR-T cells and found high tumor burden in bone marrow, lymphodepletion with cyclophosphamide and fludarabine, higher CAR-T cell dose, thrombocytopenia before lymphodepletion, and CAR-T cell manufacturing without selection of CD8+ central memory T-cells as independent predictors of CRS. This evidence concerns the gene CD19 and Thrombocytopenia.