IL21 and tuberculosis: Using the linear ANOVA approach with 2df, we found that four markers—IL-21, sCD40L, IL-8, and MMP-2 were significantly differentially expressed (under FDR of 0.05) in the comparisons between the HC and jointly analyzed TB and LTBI groups as well as between the TB and LTBI subjects, which confirmed the potential utility of these proteins in distinguishing the state of M.tb infection from the uninfected condition and active from latent TB in children.