NUCLEOLIN and lymphoma: Incubation of RMA T lymphoma (H-2b), A20 B lymphoma (H-2d), or 4T1 (H-2d) cells in vitro with nucleolin aptamer conjugated to a TAP siRNA (Nucl-TAP), but not with nucleolin aptamer conjugated to a nonfunctional siRNA (Nucl-Ctrl) or with a non-binding aptamer conjugated to TAP siRNA (Ctrl-TAP), led to downregulation of TAP mRNA (Fig. 1a) in the absence of measurable cytotoxicity (Supplementary Fig. 2).