In a study of patients with COVID-19, TF expression was found to be significantly elevated on the patient's neutrophils, in addition to the release of NET carrying active TF by neutrophils, and the complement C3 inhibitor comptincp40 was found to reduce neutrophil TF expression, suggesting that high neutrophil TF expression in this patient was associated with complement C3 [43]. Here, TF is linked to COVID-19.