Furin also enables cellular entry of several pathogenic viruses belonging to evolutionarily diverse families [122], including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative pathogen for coronavirus disease 2019, where furin cleaves a site critical for virus–host cell fusion and entry into lung cells, between the S1/S2 subunits of the spike (S) glycoprotein [123, 124]. This evidence concerns the gene FURIN and COVID-19.