F2 and COVID-19: As shown in Figure 1, we discovered that COVID‐19 patients showed higher values for the RDW‐CV (P < .01), neutrophil percentage (P < .05), and prolonged prothrombin time (PT, P < .05) compared with the control patients, and they also showed lower levels of total proteins (P < .05), lymphocytes (P < .05), eosinophils (P < .01), and mean corpuscular hemoglobin (MCH, P < .05) at the clinical recovery stage compared with the control patients.