Elevated levels of ROS and oxidative DNA damage in quiescent LSCs treated with imatinib. Lin⁻c-Kit⁺Sca-1⁺Fluor670^max quiescent HSCs/LSCs from healthy (black bars) and CML-CP–like (gray bars) mice were untreated or treated with 1 μM imatinib (−IM and +IM, respectively) followed by FACS analysis of phosphotyrosines (P-Tyr), ROS, and 8-oxoG. (A) P-Tyr was measured in 7 LSC and 4 HSC samples; *P = .039 in comparison with untreated HSCs and **P = .028 in comparison with untreated LSCs. (B) Fold change of ROS detected in 3 LSCs vs 2 HSCs samples; *P = .010 and **P = .017 in comparison with corresponding HSCs. (C) 8-oxoG was examined in 4 LSCs and 5 HSCs samples; *P = .002 and **P = .031 in comparison with corresponding HSCs.