To further test the in vivo validity of the gene expression correlations from the PCa datasets, immunohistochemical assays of FSCN1, using two independent antibodies (Fig. 3a and Supplementary Fig. S2), were used and showed that its expression was only detectable in blood vessels, either in primary prostate tumours or in lymph node and bone metastasis, samples were already described in [18, 20]. This evidence concerns the gene FSCN1 and prostate neoplasm.