TMPRSS2 and COVID-19: In COVID-19-infected subjects, nasal, lung and gut epithelial cells express ACE-2 and TMPRSS2 and a genic panel characterized by the activation of the proinflammatory gene IL-6, its receptor IL-6R, its co-receptor IL-6ST, Interleukin1 receptor (IL-1R), Tumor Necrosis Factor (TNF)-related pathways and complement genes.