CXCL13 and Sjogren syndrome: Interestingly, CXCL13 also was one of only five genes expressed in >90% of the Sjogren's patient biopsies (but <10% of control biopsies) and CXCL13 expression has been localized to ectopic follicles in salivary glands in Sjogren's syndrome, making its expression in salivary glands a possible disease marker [1,12].