Among these three candidate markers for active TB, HO-1 had the highest discriminatory power (Figure 2B) with a 23.5% higher specificity in distinguishing active from LTBI compared to SAA (94.9% vs. 71.4%, respectively) and 48.8% higher specificity compared to CRP (94.9% vs. 46.1%, respectively; Figure 2B). The gene discussed is HMOX1; the disease is tuberculosis.