Mysm1^−/− DC progenitors fail to differentiate into DC with Flt3L in vitro stimulation. DC progenitor cells Lin⁻LSKs (Lin⁻Sca1⁺cKit⁺), Lin⁻CD115⁺, and CMPs (Lin⁻IL7R⁻Sca1⁻c-Kit⁺CD34⁺CD16/32^int) were isolated from WT or Mysm1^−/− BM by FACS sorter and 10 000 progenitor cells were cultured with 1.5 × 10⁵ CD45.1 BM feeder cells in the presence of Flt3L (100 ng/mL) (A) or GM-CSF (20 ng/mL) and IL-4 (20 ng/mL) (B) in a 96-well plate for 8 days. Cells were harvested and analyzed by FACS for DC differentiation (CD11c⁺ CD45.1⁻). (C) The number of DCs (CD11c⁺ CD45.1⁻) generated from 1000 progenitors of each culture was calculated and presented as an average from 2 to 3 wells. The experiments were repeated 3 times with similar results. *P < .05; **P < .001.