this volume provides a review of current research in the field of b cell development and differentiation with particular emphasis on signal transduction processes. the volume is divided into two parts that focus, respectively, on the basic biochemical pathways which regulate b cell biology and the role of signal transduction processes in regulating various aspects of b cell function, development and differentiation. in this second part the molecular processes involved in translating bcr engagement to specific biological outcomes are reviewed. topics covered in this part include signal transduction via the pre-b cell antigen receptor complex, the control of immunoglobulin gene recombination and allelic exclusion, and molecular regulation of positive and negative selection. these latter chapters present information regarding processes which are critical for the b cell response to foreign antigen that leads to differentiation into antibody secreting plasma.