Bettina Heidecker et al. BTS 2016;1:107-121 Heat Map of Samples From All Patients With IDCM When we applied this unsupervised clustering algorithm, samples from patients on beta-blocking agents were grouped in a classification tree (highlighted in a dotted square) that was very distinct from patients who received alternative therapy. Each column represents a patient sample, and each row corresponds to a gene. Down-regulated genes are depicted in red, whereas up-regulated genes are labeled in blue. Bettina Heidecker et al. BTS 2016;1:107-121 The Authors