So et al. (2007) were the first to report decreased induction of expression of the X-box binding protein 1 (XBP1) and C/EBP homologous protein (CHOP) genes in response to ER stress stimulated by thapsigargin and tunicamycin in B-lymphocytes from BD patients compared to controls. Here, XBP1 is linked to Behcet disease.