Whereas interferon signalling upon SARS-CoV-2 infection is suggested to induce ACE2 expression in single-cell levels (27), cellular entry of SARS coronavirus leads to down-regulation of bulk amounts of ACE2 protein in the lungs and heart (36, 37), which suggests a complicated mechanism for virus spread in the tissue microenvironment during the course of de novo infection of SARS-CoV-2. The gene discussed is ACE2; the disease is infection.