Sunitinib-induced NF-κB activation in 786-O RCC cells, as demonstrated by IκBα degradation and Rel-A phosphorylation, corresponds with the eIF2α phosphorylation, upregulation of ATF4 protein expression and dephosphorylation of IRE1α (Fig. 2a). This evidence concerns the gene ATF4 and renal cell carcinoma.