The aim of this study was to assess the value of measuring and attempt a quantitative evaluation using Enzyme-Linked Immunosorbent Assay (ELISA) tests of three non-serum proteins, whose presence in the blood during COVID-19 was associated with severe disease progression: neutrophil elastase (NE), calcium-binding protein S100B, and neuron-specific enolase (NSE). This evidence concerns the gene ENO2 and COVID-19.