Riedel A, Stanger AM, Kimmich LM, Hug S, Fehn AE, Schroeder JC, Besemer B, Casadei N, Demidov G, Thapa PJ, Faul C, Hensen L, Lengerke C, Bethge W. Extensive non-clonal CAR T-cell expansion causing fatal hyperinflammatory syndrome with immune effector cell-associated hemophagocytic lymphohistiocytosis, cytokine release syndrome, and neurotoxicity syndrome. Haematologica; https://doi.org/10.3324/haematol.2025.288162 [Early view].