CXCL8 and Cowden syndrome 1: Importantly, patients with severe COVID-19 show conspicuous increases in cytokines, including interleukin (IL)-6, monocyte chemoattractant protein (MCP)-1, IL-8, tumor necrosis factor (TNF)-α, IL-1, IL-18, and IL-17, with characteristics of the cytokine storm (CS).