RIPK1 and infection: To examine the role of RIPK1 in mediating inflammation induced by SARS-CoV-2, we infected lung organoids with SARS-CoV-2 in the presence or absence of RIPK1 inhibitor Nec-1s.29,43 Nec-1s is a further structurally optimized derivative of RIPK1 inhibitor Nec-144 and demonstrates therapeutic potential in a variety of animal models of human inflammatory diseases.39 We found that the infection of lung organoids by SARS-CoV-2 promoted the activation of RIPK1 as indicated by p-S166 RIPK1 in the infected lung organoids which was blocked by Nec-1s (Fig. 2a).