Assessment of basal NRF2 activity in a panel of human tumor cell lines.

<p><b>A</b>. Schematic diagram showing characteristics of cell lines with low (upper panel), moderate (middle panel), or high (lower panel) basal NRF2 activity. <b>B.</b> Protein levels of KEAP1 and NQO1 (whole-cell lysate), and NRF2 (nuclear fraction), were evaluated by western blot. Actin (whole-cell lysate) and HDAC2 (nuclear fraction) served as loading controls. Based on KEAP1, NRF2, and NQO1 protein levels, cell lines were categorized according to their basal NRF2 activity.