EIF4EBP1 and nonpapillary renal cell carcinoma: The increase in pSer65-4EBP1 expression in response to R2TNF was commensurate with that of TNFR2 in tumor cells, as well as in vascular endothelial cells and isolated interstitial cells (Figure 2C), similar to the increase in both proteins in ccRCC tumor tissue.