“…However, selection partially corrected the defect in exonucleolytic processing, resulting in a lesser abnormality in the productive repertoire. It is well-established that NF-B regulates different aspects of B cell apoptosis (2,9,12), proliferation (10,11,48), maturation (6, 9, 13, 49 -51), survival (8,49,52), class switch and Ig gene recombination (11,14,23,35,(53)(54)(55)(56)(57). In vitro studies examining Ikk␥ Ϫ/Ϫ embryonic stem cells cocultured with bone marrow cells (52) and in vivo studies using Mb-1Cre-transgenic mice lacking Ikk␥ from the B cell progenitor stage on (48) Previous studies have shown that NF-B signaling is defective in B cells of HED-ID patients (50).…”