Keratins are used as biomarkers because their expression is often altered in cancerous cells compared to normal cells. These alterations can involve changes in the types, amounts, and distribution of keratins, which can be distinct and consistent for specific types of cancer. For instance, keratin 19 is often used as a marker in breast cancer, while keratin 7 and keratin 20 are useful in distinguishing different types of adenocarcinomas. Therefore, keratin profiling is a powerful tool for the diagnosis and characterization of malignant tumors.
