Belonging to the genus Betacoronaviridae, the virus was found to be closely related to the prior SARS-CoV responsible for the SARS epidemic, with evident similarities: both use the same transmembrane enzyme, angiotensin converting enzyme 2 (ACE2), as a viral receptor, a trimeric spike (S) glycoprotein for facilitating viral binding and entry, and the host protease transmembrane serine protease (TMPRSS2) to prime the fusion machinery and achieve cellular entry [2]. Here, ACE2 is linked to severe acute respiratory syndrome.