CRS is characterized by high levels of inflammatory cytokines. Among them, IL-6 is considered a major mediator of this hyperinflammation [18,19]. Most of the COVID-19 patients-related papers showed the CRS as one of the main hallmark of the disease [20]. Additionally, IL-6 levels predict severity in COVID-19 patients [21]. There is high heterogeneity of IL-6 values among papers for classifying severe and nonsevere patients. In a large meta-analysis of 52 manuscripts, Elshazli and coworkers found that the IL-6 level associated with COVID-19 severity was 22.9 pg/ml [22]. In a series of patients treated with itolizumab a cutoff of 28 pg/ml discriminates severe patients from nonsevere (manuscript just accepted in Immunity and Aging). In the present study, the IL-6 concentration of the three patients was above this cutoff. It confirms the classification of these patients as severe and that the CRS is probably occurring.