ANPEP and viral infectious disease: Consistent with the different binding affinities of peak 2 and peak 3 samples with hAPN receptor, our pseudovirus infection assay results also showed that peak 3 samples could more effectively inhibit viral infection than peak 2 by competitively binding to hAPN in Huh7 cells, which meant that the receptor binding ability of peak 3 (C2) was more effective than that of peak 2 (C1) (Fig. 2c).