IFNG and COVID-19: However, COVID-19 patients induced 1.7 times lower IFN-γ secretion with rhIL-12 plus PMA and 2.1 times lower with PMA stimulation alone than healthy subjects (IFN-γ pg/mL, median = PMA: 76 vs. 157, rhIL-12: 35 vs. 40, and rhIL-12+PMA: 65 vs. 110, patients vs. healthy controls) (Figure 2d).