(A) Hierarchical clustering was performed to identify groups of patients with similar RNASeq expression of 20 genes associated with reduced survivability in the TCGA GBM patient cohort. (A) Hierarchical clustering was performed to identify groups of patients with similar RNASeq expression of 20 genes associated with reduced survivability in the TCGA GBM patient cohort. (B) Patients stratified using clustering dendrogram assignment into high and low expression groups showed significant differences in survival. Heatmap z-scores were calculated per gene. Agglomerative hierarchical clustering with complete linkage was performed using Euclidean and Pearson correlation distance metrics on rows and columns, respectively. Andrea Shergalis et al. Pharmacol Rev 2018;70:412-445 Copyright © 2018 by The Author(s)‏