Emerging evidence has shown that biomarkers of platelet activation were significantly increased in COVID-19 patients and were associated with thrombosis and increased mortality in hospitalized COVID-19 patients, including CD40 ligand (sCD40L), P-selectin, the metabolite of thromboxane A2, thromboxane B2 (TxB2) [45, 46]. Here, CD40LG is linked to COVID-19.