PCA of gene and miRNA expression microarray data. The PCA graph of global gene expression data (A) and PCA graph of global miRNA expression data (B) were computed using Partek GS, version 6.6; BM control samples are shown as red spheres; PB control samples are shown as blue spheres; PMF samples are shown in green. PMF JAK2 wild-type samples are shown as pyramids, and PMF JAK2V617F samples are shown as prisms.