Figure 3: (a) HaCaT keratinocytes were stained with anti-NRF2 antibody (green) and 4,6-diamidino-2-phenylindole (blue). NRF2 was mainly localized in the cytoplasm in untreated cells. PAH induced cytoplasmic to nuclear translocation of NRF2 (arrows). (b) The proportion of keratinocytes in which NRF2 was predominantly stained in the nucleus was calculated. . (c) Transcription of HO1 mRNA was significantly upregulated by PAH. BaP did not affect HO1 expression. .