To further reinforce the fact that the elevated levels of mitochondrial O2− observed under these conditions were directly attributable to reduced LETM1 levels, we performed a similar analysis, although in this case using the human T98G glioblastoma line, with the additional element of complementation with an siRNA-resistant cDNA encoding LETM1. The siRNA oligonucleotide was designed to the 3′UTR of LETM1 and, as expected, resulted in a significant reduction in LETM1, which was also associated with elevated mitochondrial O2− (MitoTracker-SOX) (Fig. 6D,E). The gene discussed is LETM1; the disease is glioblastoma.