ESR1 and neoplasm: In addition, in our tumor ChIP-seq replicate data, we observed high correlation of read counts in known ERα binding regions [26] (Spearman's rho 0.40 and 0.41) within replicate sample pairs and low correlation in 3 un-related samples to one of the replicate samples (Spearman's rho, < 0.10) (Supplemental Figure 3E).