hMASC gene expression profile. (A) Left panel shows the unsupervised hierarchical clustering analysis for the 14 902 features of the filtered expression matrix (FEM1). hMASCs derived from the 3 different organs are characterized by the expression of a unique set of genes or transcriptional module (red vertical bar), characterized by genes up-regulated in hMASCs with respect to the profiled somatic cell lines and adult tissues. Green vertical bar highlights the existence of an opposite gene module characterized by genes down-regulated in hMASCs with respect to the profiled somatic cell lines. Right panel schematizes the sample arrangement with respect to the dendrogram. (B) Principal component analysis (PCA) of log-transformed data starting from filtered FEM1 matrix (14 902 features). In panels Bi-iii, the first 3 principal components are plotted in pairs, while in panel Biv the first 3 principal components are plotted in 3D view. The emerging sample groups confirmed that the 3 hMASC types (blue dots) constitute a homogeneous cell population, irrespective of their tissue of origin and distinct from that of somatic cell lines (red dots) and adult tissues (green dots).