KRT20

Keratin 20 (KRT20) is an intermediate filament protein expressed in normal epithelial cells of the gastrointestinal tract (colon, small intestine), urothelium, and Merkel cells. It maintains cytoskeletal integrity and epithelial cell structure. KRT20 is overexpressed in colorectal cancer, bladder cancer, gastric cancer, and Merkel cell carcinoma, with minimal expression in other normal tissues. Its tissue-specific expression makes it a valuable diagnostic marker (e.g., in circulating tumor cells) and therapeutic target. Approaches include antibody-drug conjugates and peptide vaccines, targeting KRT20+ tumor cells while sparing healthy tissues, particularly in gastrointestinal and urothelial malignancies.