ATF4 induces the target genes involved in the UPR, apoptosis, transcription, and oxidative stress. A, TT cells were treated with vandetanib (Van; 5 μM), eeyarestatin (EE; 5 μM), sunitinib (5μM) or the two drugs in combinations for 16 and gene expression was measured by qRT-PCR using indicated probes and HPRT as an internal control. Data are presented as the mean of three independent experiments ± SD. B, C MZCRC1 cells were treated with eeyarestatin (EE; 5 μM), sunitinib (5μM) or vandetanib (Van; 5 μM), or the two drugs in combination for 16 and gene expression was measured by qRT-PCR using indicated probes and HPRT as an internal control. Data are presented as the mean of three independent experiments ± SD. Unpaired two-tailed t-test, *p<0.05, **p< 0.01, ***p<0.001, ****p<0.0001. D, MZCRC1 cells treated as in B were analyzed by Western blotting using the indicated antibodies. Vinculin served as a loading control.