• If both H chain rearrangements are nonproductiveè no pre-B cell receptor è death
•In pre-B cells with a successful VDJ rearrangement, pre-B cell receptor can receive signal to halt rearrangement and to start proliferation
D to JH               VH to DJH                 VL to JL
3 stages to make functional receptor
The steps in immunoglobulin gene rearrangement at which cells can be lost