TLR4 and myalgic encephalomeyelitis/chronic fatigue syndrome: Previous studies have reported associations of BPS/IC with nonbladder syndrome, including fibromyalgia, chronic fatigue syndrome, and IBS.5,6 They suggested that sympathetic dysfunction may be their common underlying pathogenesis.6 Increasing evidence has shown that chronic inflammation is important in the development of BPS/IC, specifically in cases of high severity.7,8 A recent study reported that BPS/IC patients have reduced pain thresholds.9 Schrepf et al8 indicated that Toll-like receptor-4 (TLR-4)-mediated inflammation plays a critical role in pelvic pain of BPS/IC.