Cytokine antagonists are now concrete therapeutic options in patients with severe SARS-CoV2 respiratory failure. The Interleukin-6 (IL-6) inhibitor tocilizumab (TCZ) has shown to significantly reduce the 30-day mortality risk and the risk of mechanical ventilation, without increasing the risk of infection and/or adverse events [1]. However, 30-day mortality in patients treated with TCZ remain of about 25% [1]. Predictors of tocilizumab failure in SARs-CoV2 patients are uncertain. To tail treatment on single patient based on his or her inflammatory status could improve the rate of success, as highlighted by Levi M in a recent issue of European Journal of Internal Medicine [2].