The authors observed a significant difference in IFN-γ response between the two tubes, showing that the TB2 tube has the highest sensitivity of the two.18 A meta-analysis of 15 studies published by Sotgiu et al. showed that the QFT-Plus assay had a pooled sensitivity of 94% for active TB patients and a pooled specificity of 96% in healthy individuals.17 It was also noted that significant correlation was observed between the QIAreach QFT TTR and IU/mL responses of QFT-Plus-positive samples. This evidence concerns the gene IFNG and tuberculosis.