The light chain IgLV3-21 defines a new poor prognostic subgroup in chronic lymphocytic leukemia: Results of a multicenter study by Stamatopoulos, B, Smith, T, Crompot, E, Pieters, K, Clifford, R, Mraz, M, Robbe, P, Burns, A, Timbs, A, Bruce, D, Hillmen, P, Meuleman, N, Mineur, P, Firescu, R, Maerevoet, M, De Wilde, V, Efira, A, Philippé, J, Verhasselt, B, Offner, F, Sims, D, Heger, A, Dreau, H, Schuh, A