TBI conditioning increases circulating exMito in patients undergoing HSCT. Serial samples collected from patients undergoing HSCT before initiation of conditioning regimen (preconditioning), day of transplant (day 0), and days 7 (+7) and 14 (+14) after HSCT was evaluated for abundance of exMito in circulation. (A) MTG-positive events represented as fold induction relative to the preconditioning sample of each patient. (B) Comparison of mitochondrial levels in samples collected at the indicated times between patients with and without GVHD; ∗P < .05.