EGF and squamous cell carcinoma: We first performed far-Western blotting, a reverse-phase SH2 binding assay (Machida et al., 2007) to quantify changes in the binding sites for multiple SH2 domains across the set of phosphoproteins in EGF-stimulated A431 cells, an EGFR-overexpressing squamous-cell carcinoma cell line (Stanton et al., 1994; Wrann and Fox, 1979).