We found that 56% of tumor samples displayed no membrane staining for TRAIL-R1 and 19% for TRAIL-R2 with the extent of membrane staining varying inversely with the cytoplasmatic staining, suggesting that internalization of TRAIL-receptors could represent a mechanism for the loss of functional TRAIL receptors as a distinctive feature of pancreatic cancer cells, a hypothesis recently corroborated by other studies in vitro[11], [31]. This evidence concerns the gene TNFRSF10A and neoplasm.