The Rockefeller University Press $30.00 J. Exp. Med. Vol. 205 No. 13 2985-2994 www.jem.org/cgi/doi/10.1084/jem.20082053 2985 B cells undergo a random process of V(D)J recombination to generate the many distinct receptors needed to recognize a vast array of antigens. An inevitable consequence of this random process is the production of autoreactive B cells ( 1 ). An important mechanism for toler...