Similar NF-κB DNA binding induced by IL-9 and BCL3. MC9 mast cells transfected with either a control vector or the pEF-BOS plasmid containing the BCL3 cDNA were stimulated with 100 U/mL IL-9 for more than 24 hours or were left unstimulated. Shown is a representative EMSA performed with the palindromic NF-κB probe. An Sp1 DNA binding oligonucleotide was used as a control for the loading of similar protein quantities in each lane.