IL6 and COVID-19: A meta-analysis of multiple observational studies showed that a high NLR is associated with severity and high mortality in COVID-19 [29], possibly attributed to mechanisms by which inflammatory factors, such as interleukin-6, interleukin-8, and granulocyte colony-stimulating factor, that are elicited in SARS-CoV-2 infections may stimulate the production of neutrophils [30].