Gene expression analysis. Venn diagram summarizing pairwise comparisons of individual genes and of their expression changes in ET MKs relative to normal MKs (“low-abundance” genes and genes showing only borderline changes in expression were excluded from the analysis). “Specific” refers to genes expressed in only one cell population; “P-P” refers to genes detected in both populations, which are subdivided into those that were increased (I), decreased (D), or not changed (NC) in the ET MKs relative to their normal counterparts.