In 2016, a meta-analysis was published detailing the 5-year survival outcomes of >3600 patients across 11 different malignancies (including melanoma, breast, ovarian and lung) with results suggesting that VM content within a tumour mass (as identified by lumenised vascular structures that are low/negative for CD31 (or CD34) and stain positive with the periodic-acid Schiff (PAS) reagent) correlated strongly with poor prognosis20. This evidence concerns the gene PECAM1 and neoplasm.