The immune cells (leukocytes) infiltrating the pancreatic tumour are impaired, which is likely caused by abnormalities in the tumour vascular endothelium, particularly the reduced or altered expression of adhesion molecules such as ICAM-1 and VCAM-1, which are normally required for leukocytes to attach to and cross the vessel wall [18]. This evidence concerns the gene ICAM1 and neoplasm.