SBDS deficiency increases activation of p53 pathways in BM niche cells after myeloablative TBI. (A) GSEA plot showing overall downregulated expression of ribosomal proteins (left) and genes associated with peptide chain elongation (right) in BM stromal cells from irradiated (24 hours after 1100-cGy TBI) Mx1^CreSBDS^Exc mice vs irradiated controls. (B) GSEA plot shows overall increased activation of the p53 pathway in BM niches of irradiated Mx1^CreSBDS^Exc vs control mice (n = 5 mice per group). (C) Expression of individual p53 target genes is upregulated in BM niches of irradiated Mx1^CreSBDS^Exc vs control mice (n = 5 mice per group). FDR, false-discovery rate; NES, normalized enrichment score. *P < .05; **P < .01; ***P < .001; DESeq2 statistical test. (D) qPCR confirms upregulation of these p53 target genes in BM niche cells taken from irradiated Mx1^CreSBDS^Exc (n = 3) vs control mice (n = 4) at 24 hours after 1100-cGy TBI. *P < .05; Student t-test.