Cell cycle analysis of migrated wild-type or ITD-Flt3 Ba/F3 cells. Cells that had migrated after 4 hours were collected, fixed overnight in 1% paraformaldehyde, and stained with 1 μg/mL propidium iodide (Sigma Aldrich) in 0.6% nonidet P-40 (NP-40)/PBS with 1 μg/mL RNase (Sigma Aldrich), as described.⁴⁰  Data were analyzed using a FACScan and ModFIT and Cell Quest software (Becton Dickinson) and expressed as the mean ± SEM of spontaneously or CXCL12-induced migrating cells in S+G₂/M phase from 3 experiments. ▪ indicates wild-type Flt3; □, W51; ▨, W73; and ▦, W78. *P < .05 compared with wild-type Flt3.