Keywords: G-CSF; granulocyte colony stimulating factor; GI; gastro-intestineal; HIF-1α; hypoxia-nducable factor 1 alpha; HNT; head-and-neck-tumours; ICAM-1; intercellular adhesion molecule-1; IL; interleukin; KGF-1; keratinocyte growth factor-1; NF-κB; nuclear fa