USF proteins interact with the α-spectrin gene 183-bp exon 1′ + intron 1′ region. Quantitative ChIP analyses of the 183-bp region of the α-spectrin gene encoding exon 1′ and intron 1′ were performed with K562 cell chromatin and antibodies against USF1 and USF2. The hypersensitive site 2 of the locus control region of the human β-globin locus was included as a positive control. Negative controls include GABRA6 and an unrelated region of the α-spectrin gene downstream of the 183-bp region. ■, USF1-precipitated chromatin; ▩, USF2-precipitated chromatin; □, IgG-precipitated chromatin. Standard error bars represent results from multiple (≥ 3) experiments.