Baseline expression levels of NRF2 target genes and tumor cell responses to arsenic trioxide. (A) Baseline gene expression levels of eight NRF2 target genes in the NCI-60 tumor cell panel. For each of the nine tumor types, the average gene expression level was calculated for all the tumor cell lines within this group. The cumulative gene expression levels of the eight target genes were calculated to represent the general gene expression level of that tumor type (Leu = Leukemia; CNS = Central Nervous System; Mel = Melanoma; Ov = Ovarian; NSCL = Non-small Cell Lung; Pro = Prostate). (B) Arsenic-specific log(GI50) values of the NCI-60 tumor cell panel. For each of the nine tumor types, the average log(GI50) was calculated for all the tumor cell lines within this group to represent the general susceptibility of this tumor type to arsenic-induced cytotoxicity.