PTGS2 and colorectal carcinoma: We have therefore studied tissue biopsies obtained from patients with diagnosed primary colorectal carcinoma undergoing surgical treatment for their disease, for differences in expression of COX-2 in epithelial and stromal cells (macrophages, fibroblasts and VECs), in malignant and adjacent normal colorectal tissue, and for alterations in the expression of the upstream intracellular proteins, which seem to be associated to COX-2 expression, namely NF-κB-p65, NF-κB-p50 and IKKα.