The LPS-inducible complex was not detected using the mutant C/EBP oligonucleotide probe and could be abolished by an excess of unlabeled double-stranded oligonucleotide, carrying either the same sequence (Fig. 5B, lanes 4 and 5) or the sequence of a known C/EBP binding site from the rat albumin promoter (Fig. 5B, lanes 8 and 9), but not by the mutated oligonucleotide (Fig. 5B, lanes 6 and 7).