B cells that fail to pass a developmental checkpoint, either as immature or mature B cells, can be rescued by creating a new B cell antigen receptor through nested secondary immunoglobulin gene rearrangements, a process termed receptor editing. Tolerance-mediated receptor editing occurs in self-reactive immature bone marrow B cells, while peripheral receptor editing probably occurs in low-affinity B cells competing for antigen and for survival signals within the germinal center response.