By categorizing the different markers compared in primary tumor biopsies and paired metastasis samples into different groups we suggest that: (1) markers for genetic alterations, such as the TRMPSS2-ERG fusion gene [16], are highly correlated and largely maintained over time, (2) markers for the epithelial cell phenotype, such as proliferation and differentiation are moderately correlated, probably influenced by the tumor cell genome, bidirectional signaling to and from the tumor microenvironment, and by treatments and time, and (3) stromal markers are less correlated. Here, ERG is linked to neoplasm.