Newest article from Science Magazine: http://science.sciencemag.org/content/352/6292/1390 A single zygote with a defined DNA sequence gives rise to all the varied cells of the mammalian body. This variety of cell fates may arise in part from cell-to-cell variability in the gene expression programs of embryonic stem cells (ESCs). Three recent studies have taken different approaches to characterizing this variability in gene expression in stem cells. These results suggest that microRNAs (miRNAs)…