Ectopic activation of Fbp2 in Setdb1-deficient HSPCs. (A) RT-PCR of Fbp1 and Fbp2 expression in the indicated cells from WT mice. mRNA levels were normalized to Hprt1 expression, and relative expression levels are shown as the mean ± SD of triplicate analyses. ND, not detected. **P < .01. (B) RT-PCR of Setdb1 and Fbp2 expression in the indicated organs from WT and Setdb1^Δ/Δ mice 7 days after the first injection of tamoxifen. mRNA levels were normalized to Hprt1 expression, and relative expression levels are shown as the mean ± SD of triplicate analyses. **P < .01. (C) A western blot analysis of Fbp1 and Fbp2 protein expression in GMPs from WT and Setdb1^Δ/Δ mice 2 weeks after the first injection of tamoxifen. Liver and muscle were used as references, and β-actin was probed as a loading control. The arrowhead indicates a cross-reactive Fbp1 signal in lane 1. (D) Immunostaining of Fbp2 in CD34⁻LSK HSCs, LSK HSPCs, and GMPs from WT and Setdb1^Δ/Δ mice 2 weeks after the first injection of tamoxifen. Cells were counterstained with DAPI. Representative images are depicted.