Correlation of nectin-1 expression with viral titers. Pearson’s correlation coefficients (a–e) were calculated between the viral titering data from M2001, C134, C101, R7020, G207 (Supplementary Figure 1) and the nectin-1 expression levels (f) from cell lines 90-8-luc (open triangle), STS26T-luc (closed diamond), T265-luc (open circle), YST-1 (closed square), 88-14-luc (open diamond), NMS2-PC (closed triangle), S462-luc (open square), and 2xSB (closed circle). A strong and significant correlation was noted for M2001. Cells were infected in triplicate by a single-step replication assay (MOI =10) and the lysates collected and titered at 24 h.p.i. Nectin-1 expression was quantified by flow cytometry after incubation with phycoerythrin (PE)-conjugated mouse monoclonal antibody with subsequent quantification using antibody quantification beads. The percentage of the cell population staining above the isotype control is also reported. Receptor quantification was performed in triplicate with the standard deviation reported.