BACH2 mediates negative selection and p53-dependent tumor suppression at the pre-B cell receptor checkpoint

During B cell development, cells that fail to productively rearrange their immunoglobulin VH-DJH gene segments to generate an in-frame junction that codes for a functional pre-B cell receptor are deleted. Markus Müschen and colleagues now report that Bach2 is a key component of this pre-B cell receptor checkpoint that enables the elimination of normal and transformed B cells with nonfunctional V(D)J rearrangements by regulating the expression of p53.