PTGS2 and colorectal cancer: We have therefore examined tissue biopsies obtained from patients with diagnosed primary colorectal cancer undergoing surgical treatment for their disease, for differences in the expression of COX-2 in malignant and adjacent normal epithelial cells, and for alterations in the expression of the upstream intracellular proteins that appear to be linked to COX-2 expression, specifically NF-κB and IκB kinase α (IKKα).