The Renin-Angiotensin-Aldosterone System (RAAS) has been shown to be central in COVID-19, since three of the key modulators of SARS-CoV-2 infectivity–angiotensin 1–7, ACE2, and AT1—belong to the RAAS, in addition to the TMPRSS2 expression (12–19). The gene discussed is TMPRSS2; the disease is COVID-19.