The GC is required for B-cell lymphomagenesis in pEμ-B29-TCL1 transgenic mice. Kaplan-Meier survival plot is shown. WT (n = 20), TCL1-tg (n = 22), OCA-B^–/– (n = 23), and TxO (n = 25) mice were monitored up to 20 months or until they became moribund, followed by killing and necropsy.