TNF and inflammatory bowel disease: PHD1 was significantly up-regulated in IBD patients, both at the mRNA (UC: p < 0.0001 and CD: p < 0.05) and at the protein level (UC: p < 0.05 and CD: p < 0.05), and showed a very good correlation with the expression of the inflammatory cytokines IL-8 and TNF-α and the apoptosis marker caspase 3.