Patterns for ERG expression were moderately to highly correlated, but there were some datasets with inverse correlation, such as Ren et al. 53 and Sun et al. 51,52, and Ren et al. and Barwick et al. 42,43 While datasets with gene expression from metastatic tumors are few, the pattern of correlation between Chandran et al. 54,55, Abida et al. 56, and Taylor et al. 4,39 were lower, likely due to the intrinsic heterogeneity of measuring gene expression from samples in the metastatic setting. The gene discussed is ERG; the disease is metastatic neoplasm.