CAV1 and renal cell carcinoma: In this study we show a positive correlation in primary RCC tumours between the over-expression of Cav-1 and pERK-1/2, their co-expression in localised tumours a powerful biomarker combination able to stratify patients into low, intermediate and high risk of developing mRCC including recognising high risk patients whose primary tumours displayed low grade and/or low stage disease.