If the sensitivity of 92.3% and specificity of 75% (Table 3) for predicting progression from latent to active TB is corroborated in additional studies, monitoring NPC2 expression in blood can contribute to the detection and early treatment of those LTBI cases at risk of progression to active TB by using a simpler method, (RT) qPCR, which was already validated for this marker [10]. The gene discussed is NPC2; the disease is tuberculosis.