A, Western blots of cell lysates from NCI-H1373 cells and AHR knockout pools. B, Dose response curves of parental and AHR-knockout NCI-H1373 cells treated with RBN-2397 for 7 days. Data shown as mean values ± SD; n = 3. C, Dose response curves of parental (left) and AHR-knockout NCI-H1373 cells (right) treated with RBN-2397 alone or combined with indicated concentrations of CH-223191/L-kynurenine. Data shown as mean values ± SD; n = 3. D, Western blots of cell lysates from NCI-H1373 parental cells and cells induced to express a myc-tagged AHR cDNA transgene. E, Growth curves showing the effect of doxycycline-induced AHR overexpression. Data shown as mean values ± SD; n = 15.