PTGS2 and neoplasm: Among the most downregulated molecules, SIGIRR (single immunoglobulin domain-containing IL1R-related protein), TOLLIP (tool interacting protein), and PTGS2 (prostaglandin-endoperoxide synthase 2, known also as COX2) emerged as significantly lower in tumor samples, as well as PPARA (peroxisome proliferator activated receptor gamma), MAPK8 (mitogen-activated protein kinase 8), and NR2C2 (nuclear receptor subfamily 2 group C member 2).