(A) ChIP of the HO-1 proximal E-box of HK-2 cells induced with haemin or vehicle. PCR for all ChIP assays was performed on immunoprecipitated samples, electrophoresed, transferred on to a nylon membrane and subsequently hybridized with a nested oligonucleotide as described in the Experimental section. (B) ChIP of primary HPTCs treated with haemin (H, 5 μM), cadmium chloride (Cd, 10 μM) or vehicle (V). (C) ChIP performed on the human HO-1 internal E-box located in intron 2. (D) DMS in vivo footprinting of the HO-1 internal E-box-transcribed strand. The E-box and flanking sequences are illustrated.