EGFR and breast adenocarcinoma: Collectively these results for the cell-ELISA analyses serve to validate the retained selective binding-avidity of gemcitabine-(C4-amide)-[anti-HER2/neu] and gemcitabine-(C4-amide)-[anti-EGFR] for external membrane HER2/neu receptor sites highly over-expressed at 1 × 106/cell on the exterior surface membrane of mammary adenocarcinoma (SKBr-3) populations (Figure 3) [24].