Notably, the contact ratio of binding sites of the MAb DXP-604, ACE2 and the RBD is 85%, as revealed by cryo-EM structures, which means that if the mutation site of the mutant prevents DXP-604 from binding to the RBD, it will be difficult for the mutant to bind to ACE2 itself, inhibiting invasion and infection of human cells. The gene discussed is ACE2; the disease is infection.