EGFR and non-small cell lung carcinoma: We conjugated molar ratios from 1:1 to a 1:100 (Fig. 1A and Supplementary Figs. 1 and 2) excess of SMCC-protamine over IgG and checked the gel-electrophoretic properties of the resulting conjugates (Fig. 1B and Supplementary Fig. 2B), their respective ability to bind siRNA (Fig. 1C–H and Supplementary Fig. 2C–F), and the internalisation of fluorescently tagged siRNA into EGFR-expressing NSCLC cells (Fig. 1I–N and Supplementary Fig. 2K–N).