Gene expression profiling reveals a close relationship between follicular lymphoma grade 3A and 3B, but distinct profiles of follicular lymphoma grade 1 and 2 oleh Heike Horn, Christian Kohler, Raphael Witzig, Markus Kreuz, Ellen Leich, Wolfram Klapper, Michael Hummel, Markus Loeffler, Lorenz Trümper, Rainer Spang, Andreas Rosenwald, German Ott, for the Molecular Mechanisms in Malignant Lymphomas (MMML) Network Project