Correlation between carbonic anhydrase IX (CAIX) and miR-210 expression. Measurements of CAIX mRNA and miR-210 expression were determined by qPCR and normalised to β-actin mRNA expression and an average of RNU43 and RNU48 expression, respectively. qPCR for each sample was performed in triplicate. A significant positive correlation is observed between the mean normalised expression of CAIX and miR-210 (r = 0.527, P = 0.002). Data are displayed on log10 axes. Shaded circles indicate tumours which have VHL mutation and/or VHL promoter methylation, and open circles represent tumours for which no VHL defect has been identified.