In the case of SARS-CoV infection, it has been shown that the virus invades human cells via this ACE2 receptor [15] and that TMPRSS2 and ADAM17 compete for ACE2 cleavage but only processing by the former promotes SARS-CoV Spike protein (SARS-S)-driven entry [44]. The gene discussed is ACE2; the disease is severe acute respiratory syndrome.