IFNG and infectious disease: One method for assessing the T‐cell's response to SARS‐CoV‐2 is the interferon‐gamma (IFN‐γ) release assay (IGRA), which is a blood‐based test for diagnosing infectious diseases by measuring the IFN‐γ secreted by antigen‐specific T‐helper cells (Th cells) in blood samples.7