Figure 2. Four distinct marker clusters can be stratified from three putative breast cancer subtypes.

Marker heatmap showing the average expression (z-score) of 112 marker genes across the three molecular subgroups identified in panel A. Each row represents an individual gene. Marker genes were identified by using an ANOVA to identify genes that are differentially expressed across molecular subtypes. Differentially expressed genes were defined as those with an FDR-adjusted p-value < 0.01 and a log2 fold-change > 4 between the lowest and highest expressing subtype. Hierarchical clustering was used to define four groups of marker genes with similar expression patterns across subtypes.