Rare exceptions have been the application of chemotherapeutic-resistant metastatic melanoma M21 (covalent daunorubicin immunochemotherapeutics synthesized using anti-chondroitin sulfate proteoglycan 9.2.27 surface marker); [63] [64] [113] chemotherapeutic-resistant mammary carcinoma MCF-7AdrR (covalent anthracycline-ligand chemotherapeutics utilizing epidermal growth factor (EGF) or an EDF fragment); [114] and chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3) populations (epirubicin-anti-HER2/neu, [16] [18] [25] epirubicin-anti-EGFR, [16] gemcitabine-HER2/neu [19] [24]) respectively. The gene discussed is ERBB2; the disease is breast carcinoma.