Nrf-2/p18 heterodimers have the same DNA binding specificity as NF-E2. A gel mobility shift assay was performed on in vitro–translated p45/p18 NF-E2 (lanes 1 and 2) and Nrf-2/p18 heterodimers (lanes 3 and 4) and on nuclear extract from untransfected COS cells, as a source of AP-1 binding activity (lanes 5 and 6). The discriminatory mutant probe (M) differs from wild-type (WT) at one nucleotide.39