Relative gene expression levels and genomic gain of EZH2 in the different subtypes. (a) Relative expression levels of EZH2 across subtypes. Basal-like tumours had the highest expression of EZH2. P-value was calculated using analysis of variance for all subtypes. (b) Fraction of samples with gain of EZH2. Gain of this gene is more frequent in basal-like tumours. P-value was calculated using Fisher's exact test between basal-like and the other subtypes. The number of tumours in each subtype is shown at the top.