Given its specific role in the final addition of the Rieske protein on the already dimeric pre-complex III (pre-cIII2) [40], the importance of the assembly factor TTC19 in tumor cells highly relying on complex III function, as suggested by our analyses, can be justified; whereas TRAP1 could be important in glycolytic tumor cells for “salvage” respiration when glucose is unavailable. Here, TTC19 is linked to neoplasm.