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Figure S4. Binding of Necl-Fc fusion proteins to Necl-expressing cells. (A) Binding of Necl-Fc fusion proteins to Necl-expressing CHO cell lines. Conditioned media from 293T cells transfected with Necl-Fc cDNAs was incubated with transfected CHO cells and washed, and binding was detected with an anti-human IgG antibody (red). Staining for the HA epitope is also shown (green). Bar, 50 µm. (B) FACS data showing Necl-1-expressing cells incubated with Necl-Fc constructs and then stained with a fluoresceinated anti-human IgG antibody. Necl-2-Fc and, in particular, Necl-4-Fc strongly bind to the Necl-1-expressing cells. (C) Binding data showing the binding of Necl-Fc constructs to Necl-3-expressing cells analyzed by FACS (mean ± SEM [error bars]). (D) Summary of binding for the whole Necl family, including data on Necl-3 interactions, scored as no binding to cells (-),