Notably, inflammatory cytokines in mouse sera, including Interleukin 6 (IL-6) and Keratinocyte chemoattractant (KC)/growth-regulated oncogene (GRO), were remarkably upregulated, while IL-2 and IL-5 were significantly downregulated after BMA8 or C57MA14 infection in mice compared to that of the uninfected group (Figures 4A, B), as seen in the severe COVID-19 patient serum. Here, IL6 is linked to COVID-19.