Pre-treatment of 293T-ACE2 cells with HSase or infection in the presence of 2 μM heparin both inhibited the SV2-S G614 pseudovirus entry into the 293T-ACE2 cells, showing that the infection by the SV2-S G614 mutant depends on host cell surface HS and can be inhibited by heparin (Figure 5D). The gene discussed is ACE2; the disease is infection.