For example, IL-6 concentrations in COVID-19 average around 36.7 pg/mL, compared with nearly 100-fold higher levels in CAR-T cell–induced cytokine release syndrome and even higher levels in sepsis and ARDS (Eljaaly et al., 2021; Leisman et al., 2020; Yu et al., 2021). Here, IL6 is linked to COVID-19.