Related Experiment Video
Updated: May 13, 2026

Isolation of Precursor B-cell Subsets from Umbilical Cord Blood
Published on: April 16, 2013
Birth pangs: the stressful origins of lymphocytes
1Center for Cancer Research, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02129, USA. pillai@helix.mgh.harvard.edu
Inositol-requiring enzyme 1 (IRE1) is a transmembrane protein that signals from the ER and contributes to the generation of an active spliced form of the transcriptional regulator X-box-binding protein 1 (XBP1). XBP1 is required for the terminal differentiation of B lymphocytes into plasma cells, and IRE1 also participates in this differentiation event. A study in this issue of the JCI reveals, quite unexpectedly, that IRE1 is also required early in B lymphocyte development for the induction of the machinery that mediates Ig gene rearrangement.
Inositol-requiring enzyme 1 (IRE1) is a transmembrane protein that signals from the ER and contributes to the generation of an active spliced form of the transcriptional regulator X-box-binding protein 1 (XBP1). XBP1 is required for the terminal differentiation of B lymphocytes into plasma cells, and IRE1 also participates in this differentiation event. A study in this issue of the JCI reveals, quite unexpectedly, that IRE1 is also required early in B lymphocyte development for the induction of the machinery that mediates Ig gene rearrangement.
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