NUCLEOLIN and cancer: AT11 G-quadruplex, as an AS1411 analogue,recognizes with high efficiency the protein nucleolin overexpressedon the surface of several cancer cell lines, and this recognitionallows the selective uptake of the aptamer into cancer cells.,,, Here, we proved that the AT11 G-quadruplex could be efficientlyinternalized also in AGS cells, being mainly localized in the cytoplasm,and promoted the entry of nucleolin into the nuclei, finally producinga time- and dose-dependent decrease in cell viability.