One of the main predisposing factors for the severe course of COVID-19 is increasing patient age, which is associated with higher expression of angiotensin-converting enzyme 2 (ACE-2) (a receptor for the SARS-CoV-2 spike protein), immune dysregulation, changes in microbiota, lower levels of steroid hormones, and senescence-associated oxidative stress [2]. The gene discussed is ACE2; the disease is COVID-19.