Division of B Cell Immunology, German Cancer Research Center, Feld 280, Heidelberg, 69120, Germany. k.imkeller@dkfz-heidelberg.de.|Department for Computational Molecular Biology, Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, Berlin, 14195, Germany. arndt@molgen.mpg.de.|Division of B Cell Immunology, German Cancer Research Center, Feld 280, Heidelberg, 69120, Germany. h.wardemann@dkfz-heidelberg.de.|Division of B Cell Immunology, German Cancer Research Center, Feld 280, Heidelberg, 69120, Germany. christian.busse@dkfz-heidelberg.de.