Pyroptosis was found in COVID-19 patients with increases of IL-1β and IL-18 [39], which further promoted the secretion of pro-inflammatory cytokines such as IL-6, IFN-γ, MCP-1/CCL2, MIP-1α/CCL3, MIP-1β/CCL4 [39,40,41]. The gene discussed is CCL4; the disease is COVID-19.