The HSPC compartment of Tgfb2^+/− mice is hyporesponsive to FLT3L in vivo. Fold increase in LSK cell number, BM and spleen cellularity, common lymphoid progenitors (CLPs; lineage⁻IL7Rα⁺Kit^loSca1^lo), common dendritic progenitors (CDPs, lineage⁻Kit^loFLT3⁺CD115⁺) in the BM, and LSK cells and DCs (CD11c⁺) in the spleen in Tgfb2^+/− mice and wt littermates after 10 days of FLT3L treatment in vivo. Data are presented as fold expansion in FLT3L-treated mice compared with controls treated with MSA only, from 3 independent experiments, each including 2-4 mice per group and per genotype, with 3 different batches of FLT3L.