Boxplot of miR-30* relative quantities in benign (BEN, clear), bone metastases (BM, dark), metastases free (MF, dashed) and visceral and bone metastases (VBM, shaded) tissues using different normalisation strategies. (Q. rel = E -ΔΔCt). The boxes represent the interquartile range. The line drawn through the boxes represents the median. Whiskers extend to the highest and lowest values in the data set. (A) miR-30* normalised using each EC individually. MiR-30* expression was significantly different between the tissue subgroups (P < 0.05) except when using miR-26b as a single EC. (B) miR-30* normalised using geNorm's top two recommended ECs (2 × ECs = let-7a and miR-16) and geNorm's top five recommended ECs (5 × ECs = let-7a, miR-16, miR-26b, miR-21 and RNU48). miR-30* was differentially expressed between groups using either the top 2 or the top 5 most stable ECs (p < 0.05). A significant difference was detected between the MF and VBM groups using the 5 EC gene approach, this was not detected when using the top 2 ECs for normalization.