After adjustment for PC levels, median APC/thrombin, APC/F1+2, and APC/TAT ratios were 2-fold (p = 0.036), 6-fold (p = 3 × 10−7) and 3-fold (p = 8 × 10−4) lower in the COVID-19 group than in the non-COVID sepsis group, and the latter two were also lower in the COVID-19 group than in stimulated healthy controls. The gene discussed is TAT; the disease is COVID-19.