Albeit only a small percentage of EVs was associated with PF4 (COVID-19, 3.0 [3.0–4.0] %; healthy controls, 2.0 [0.5–3.0] %), PF4+ EVs were significantly elevated in COVID-19 patients compared to healthy donors (7525 [3878–16,385] vs. 1050 [170–2280] EVs/μL). The gene discussed is PF4; the disease is COVID-19.