Phenotypic characterization of HSC and progenitor compartment in Ku70^−/−mice. BM cells from 3-month-old Ku70^−/− mice and WT littermates were assayed by multiparameter fluorescence-activated cell sorter (FACS) for proportion of HSC and progenitor populations. At least 6 mice per genotype were compared. Representative FACS pregated profiles of live, lineage-negative cells and frequencies of each indicated population are shown, and the absolute numbers of each population were calculated by multiplying the BM cell numbers with frequency. (A) Hematopoietic progenitors (lin⁻, Sca1⁺, c-Kit⁺ [LSK]), (B) long-term HSCs (LT-HSCs) (LSK, CD34⁻, Flk2⁻), and (C) signaling lymphocyte activating molecule (SLAM)-LSK. Significance was determined by a 2-tailed Student t test. Error bars indicate the standard deviation (SD). *P < .05.