Our aims were to investigate the expression of the regulatory hydroxylases, PHD1, PHD2 and PHD3 in tumours from patients at baseline and post treatment, to correlate the expression of these factors with clinicopathological parameters, to explore the potential of these factors as biomarkers for predicting tumour response, and to explore the association between changes in their expression and survival. This evidence concerns the gene EGLN3 and neoplasm.