In addition, the plasma concentrations of both IL-26 and IL-8 displayed a negative correlation with the mean corpuscular hemoglobin (MCH) in whole blood from the COVID-19 group (Figures 4B, C), while IL-6 and TNFα failed to correlate with MCH in this way (Supplementary Figures 9A, B). The gene discussed is IL26; the disease is COVID-19.