In our hospital, two commercial kits of IGRAs were used clinically, including QuantiFERON-TB Gold In-Tube (QFT-GIT) (QIAGEN, Germany), which measures the concentration of IFN-γ via an Enzyme-linked Immunosorbent Assay (ELISA), and X.DOT-TB (Signature Biotechnology, China), which measures the frequencies of IFN-γ-secreting cells via Enzyme-linked Immunospot Assay (ELISPOT) [6]. Here, IFNG is linked to tuberculosis.