Similarly, no COVID-19 plasma exposure triggered significant endothelial IL-6 production, which ranged from 23.3 ± 8.3 pg/ml to 25.6 ± 6.3 pg/ml for control plasma and 27.7 ± 10.4 pg/ml to 35.4 ± 20.8 pg/ml for TPE plasma (Figure 4B). This evidence concerns the gene IL6 and COVID-19.