Of note, serum H2S levels were found to inversely correlate with IL-6 as well as with the severity and final outcome of pneumonia in a cohort of patients with COVID-19, suggesting that the reduction of H2S bioavailability may be considered a biomarker of enhanced pro-inflammatory response, whereas exogenous administration of H2S could represent a valuable strategy to counteract severe manifestations of the infection [90,91]. This evidence concerns the gene IL6 and COVID-19.