In order to establish a profile of gene expression of tumours overexpressing PRH we performed agilient microarray analysis on four 4T1 tumour samples engineered to overexpress PRH, and four control tumours with normal PRH expression. cancer, colorectal metastasis to the liver and matched healthy tissues. The tumours had recieved no treatement prior to resection. The expression profiles were compared by one colour microarray analysis between PRH overexpression and control tumours. Genes consistently differentially expressed between the groups were taken forward for further analysis. Preparation of the tumours: 4T1 cells were infected with Adenoviral-PRH or empty Adenovirus at MOI 50 for 24 hrs. Adenoviral constructs described in Kershaw, R.M., et al., PRH/HHex inhibits the migration of breast and prostate epithelial cells through direct transcriptional regulation of Endoglin. Oncogene, 2014. 33(49): p. 5592-600. Cells were washed 4x with PBS, trypsinised, washed and resuspended in Opti-mem? (Invitrogen) at 1.25x106 cells/ml and kept on ice for 20-30 min before injection. Aliquots 200 μl / 2.5x105 of the cells were injected into the no. 3 fat pad of 6-8 week old female BALB/C mice. Total RNA was extracted from each tumour using the Qiagen miRNAeasy kit, processed into cRNA using the Agilient low input, one colour labelling kit, hybridised onto the 8 x 66k whole human genome expression microarrays. Data was normalised in R64 and comparison matrices between matched Tumour and Healthy endothelum were constructed. Genes upregualated in all the comparisons were taken forward for further analysis.