Hierarchical clustering for PAM results. Unsupervised hierarchical clustering using the 15 probe sets identified by PAM analyses on the training set. Each column identifies a patient, each row a probe set. The upper dendrogram separates AML (red and blue labels) from ALL (green and orange) samples. Each group further divides into MLL-positive and MLL-negative samples. The dendrogram on the left groups probe sets according to phenotype- and MLL translocation-related signatures.