IL6 and Bartsocas-Papas syndrome 1: While IL-6 elevation is not specific for IC/BPS-HL [25], and the small difference between UC and patients with IC/BPH-HL may make the design of a clinical test difficult, our observation of increased IL-6 levels is consistent with B cell infiltration into the bladder and provides an important piece of evidence about the immunology of the disease.