Supervised clustering analysis of MLL-rearranged infant ALL, MLL germline infant ALL, and pediatric precursor B-ALL. (A) Heatmap visualizing differential gene expression separating MLL germline infant ALL (n = 14), from MLL-rearranged infant ALL (n = 59) and pediatric precursor B-ALL (n = 16) samples, based on the 50 most significantly up-regulated probe sets for each patient group (compared with the other patient groups combined). Columns represent patient samples, and rows represent the gene names corresponding to the probe sets. Normalized gene expression is depicted in red (high expression) or blue (low expression). (B) Graphical representation of the supervised clustering of the samples based on this expression signature. Red dots indicate MLL-rearranged infant ALL; green dots, MLL germline infant ALL; and blue dots, the pediatric precursor B-ALL samples.