As the experiments described so far strongly suggest that the same glycan-AuNPs system might interact with different receptors of each cell line (galectin or GLUT receptors for MDA-MB-231 and SK-BR-3, respectively), the interaction of the cancer cell lines with Gal-PEG3-/ce6-PEG4-AuNPs in the presence of different galactose-binding protein inhibitors was tested. Here, GAL is linked to cancer.