The DR score is significantly increased in tumor cells after low-dose radiation. Nalm6 samples were cultured independently and treated with either low-dose radiation (1.8 Gy, n = 5) or sham (0 Gy, n = 8) treatment, followed 24 hours later by RNA-seq, GSEA, and DR score determination. (A) GSEA of hallmark gene sets and the DR score gene set enriched in 1.8 Gy low-dose radiation compared with sham-treated Nalm6 cells. False discovery rate <5%. (B) Individual samples (columns) and genes (rows) comprising the DR score are shown as a heatmap. (C) DR score charted by treatment condition.