It is suggested that factors regulating the balance of the major components of RAS, including ACE2 gene polymorphism, therapy with RAS blockers (ACE inhibitors and angiotensin receptor blockers) — may affect the severity of COVID-19.AIM: The aim of the study was to investigate the effect of RAS components, the relationship of ACE2 gene polymorphism rs2106809 and ACEi/ARBs therapy with the COVID-19 severity.MATERIALS AND METHODS: The study included patients with COVID-19 hospitalized in Endocrinology research centre (n = 173), who were divided into groups of moderate and severe course. The gene discussed is ACE2; the disease is COVID-19.