The transcriptomic response of isolated HSPCs in naïve and polytrauma mice. (A) Conditional principal component analysis of young PT mice, old PT mice and naïve miR expression patterns. (B) Heat map (log2) of the hierarchical clustering of HSPC miR expression patterns between old and young PT and naïve mice. Supervised analysis identified 198 miRs (p<0.05) that defined our groups (PT old, naïve old, PT young, naïve young). C, CTL = Control; Y, YNG = young; O = old; P, PT = polytrauma