Effect of sampling method on the expression of VEGF family members in healthy colon tissue samples. Relative mRNA expression levels of VEGF-A (A), VEGF-B (B), VEGF-C (C), VEGF-D (D) and PlGF (E) are shown for healthy colon biopsies and healthy colon resection samples. Expression levels were normalized against reference genes TBP and SDHA and were scaled against the median of the biopsy samples (median set to 1). Expression data are depicted as scatter plots of the values obtained for each individual sample. The horizontal line represents the median; ***: p < 0.001 with Mann–Whitney U Test.
Pringels et al. BMC Cancer 2012 12:515 doi:10.1186/1471-2407-12-515