It is not the aim of this review to summarize all these data, available elsewhere (1, 2), but we should highlight that SARS-CoV-2 infection is determined by the interaction of its spike protein with angiotensin converting enzyme 2 (ACE2) and further needs of transmembrane protease serine 2 (TMPRSS2) to initiate fusion and cell infection (3), although other receptors and proteases have been also involved (3–9). The gene discussed is TMPRSS2; the disease is infection.