The immunoliposomes were internalized extensively within tumour cells (92% of analyzed cells vs. <5% for nontargeted liposomes), and treatment with anti-EGFR immunoliposome-doxorubicin produced substantial tumour regressions and was the most efficacious treatment in both the EGFR-overexpressing tumour model featuring MDAMB-68 human breast tumour and U87 human glioblastoma xenografts as compared to non-targeted liposomes or free doxorubicin. This evidence concerns the gene EGFR and breast neoplasm.