HEK293 cells were infected with lentiviruses containing negative control shRNA (shNC) or NF45/NF90 specific shRNA (shNF45#1, shNF45#2, shNF90#1 and shNF90#2) for 24 h, and then transfected with rDNA-Luc. Luciferase activity was measured after a further 24 h (n = 3). Western blots show the protein levels of NF45 and NF90.