Moreover, MX1 is included as a calculator of “inflammation index” highly expressed in COVID-19 patients with a high diagnostic yield [21] and suggested as a good respiratory biomarker due to its interaction with TMPRSS2. However, here according to severity or clinical parameters, we could not find differences in rs469390 of MX1 gene, although by its interaction with TMPRSS2 was suggested to be a good respiratory biomarker [22]. This evidence concerns the gene TMPRSS2 and COVID-19.