In that sense, it has been reported that the host genetic polymorphisms such as ABO, Human Leukocyte Antigen (HLA), IL-6, complement and angiotensin-converting enzyme 2 (ACE-2) genes may be associated with SARS-CoV-2 susceptibility and COVID-19 severity (15, 174–178). The gene discussed is IL6; the disease is COVID-19.