The development and repertoire of B-1 cells (CD5 B cells).

A small subset of mouse and human B cells produces much of the serum immunoglobulin, including many common autoreactive antibodies, and accounts for most cases of B-cell chronic lymphocytic leukemia. An exciting recent conference* focused on the development, repertoire and lineage classification of these cells. The meeting was convened for a discussion of 'CD5 B cells' but ended with a discussion of 'B-1 cells'.