ACE and sarcoidosis: Among the diagnostic biomarkers for distinguishing sarcoidosis from healthy control, the following have been independently validated: serum and CSF soluble interleukin-2 receptor (sIL-2R) (AUCs: 0.67 - 0.90) (23, 37, 44, 46–49, 55), urinary U-8-OHdG (AUCs: 0.87 - 0.98) (41–43), serum angiotensin converting enzyme (ACE) (AUC: 0.78-0.88) (23, 44, 46, 55), serum chitotriosidase (AUC: 0.89) (30, 35, 40), serum KL-6 (AUC: 0.79-0.83) (18, 50), serum CRP (AUC: 0.72-0.95) (46, 50), and serum BNP (0.85-0.91) (39, 45).