Previously, we have shown that in ErbB2-positive SKBR3 breast cancer cells, inhibition of nucleolin by treatment with GroA (AS1411), a G-rich oligonucleotide21, reduces ErbB2 phosphorylation, and impairs cell viability and colony formation;20 however, cells overexpressing both ErbB2 and nucleolin were less susceptible to these effects of GroA. This evidence concerns the gene ERBB2 and breast carcinoma.