NFE2L2 and colorectal carcinoma: To determine the effects of QC and 5-FU, alone and in combination, on Nrf2 expression in CRC cells, we incubated HCT116 and RKO cells with each drug alone and with an equimolar combination of QC (0–5 μM) and 5-FU (0–5 μM) for 1 h in normoxia.