<i>HER2</i> distribution across subtypes in the METABRIC data sets.

<p>(A) Discovery and (B) Validation. The bars represent the number of samples with <i>HER2</i> amplification (positive or negative) for each intrinsic subtype based on the patients’ clinical information. The top row is based on the original subtype labels obtained with the PAM50 list and a single classifier (PAM). Middle and bottom rows are based on the labels obtained by Ensemble Learning using the PAM50 and CM1 lists, respectively.