Microarray analysis performed with the TIGR MeV program: hierarchical clustering. Microarray analysis of cultured GBM cells and generating tumor xenografts with nodular-like growth pattern, NL-type (PT1-3) or highly diffuse and invasive growth pattern, HD-type (PT4-6). Heat map visualization obtained by hierarchical clustering (HCL). Probes corresponding to genes with similar regulation trend were placed close to each other as well as patient’s samples with overall similar gene expression pattern. The color-ratio bar at the bottom indicates intensity of gene up-regulation (red), down-regulation (green) and no change (black). Affymetrix Probes identification 7 digit numbers (Probe Id) along with Gene Symbols are shown on the right. Gene name symbols used are those approved by the Human Genome Organization Gene Nomenclature Committee (http://www.genenames.org/).