Flagellin induces LSK cell proliferation ex vivo. Whole bone marrow cells from WT B6 mice were incubated in complete RPMI with or without 50 ng/mL flagellin for 15 hours. The cells were then labeled with 10 µM BrdU for 1 hour and analyzed by flow cytometry. Representative flow cytometry plots comparing LSK proliferation (A), LSK cell percentage in bone marrow (B), LSK cell number in bone marrow (C), and BrdU incorporation (D) in PBS-treated vs flagellin-treated bone marrow cells are shown. Statistics were analyzed by unpaired Student t test (***P ≤ .001). Error bars represent SEM.