We examined a second ERα+ tumor profile dataset from Wang et al. [20] and identified 50 genes from cluster B that were significantly correlated with PGR (p < 0.05) in both the van de Vijver and Wang datasets (Figure 3), where about half the number of genes would have been expected by chance (p < 0.0001, Fisher's exact). This evidence concerns the gene ESR1 and neoplasm.