Binding activity and motif logo of RELA and NFκB1. (a) The basal and inducible binding activity of RELA or NFκB1 were tested using TransAM NFκB family kit in UM-SCC 1, 6 and 22B cells after TNF-α (2000 units/ml) treatment. 'Raji' and 'Neg' represent positive and negative controls, respectively. (b) Binding activity of RELA and NFκB1 in the promoter of NF-κB target genes. The promoter sequences with putative RELA or NFκB1 binding sites were synthesized as 50-mer oligos and biotin labeled, and the assays were performed using TransAM flexi NFκB family kit. *P < 0.05 compared with the control (t test). (c) Motif logos of RELA and NFκB1 were generated from 202 and 151 genes differentially expressed in UM-SCC with their putative binding sites, respectively (upper panels). Motif logos of RELA and NFκB1 from Transfac were included for the comparison (lower panels).