However, observations in the present study of increased amount of mitochondrially encoded Cox1 in ccRCC organ cultures after TNFR2 stimulation, in addition to nuclear-encoded Cox4 and Cox5b, suggest that TNFR2-induced cell cycle entry in ccRCC is dependent on an increased energy demand that is met in part by mobilization of cytoplasmic and mitochondrial translational initiation complexes. This evidence concerns the gene COX5B and nonpapillary renal cell carcinoma.