KRT13 is a type 1 intermediate filament protein located on chromosome 17-q21.2 1 that maintains epithelial homeostasis and tissue organization. In healthy airways, KRT13 is associated with dividing cells resembling "hillock" cells and squamous differentiation 2. During viral infection, KRT13+ nasal epithelial cells interact with tissue-resident memory T cells via the CXCL16-CXCR6 axis 3. In normal esophageal epithelium, SOX2 promotes KRT13 expression as part of squamous differentiation programs 4. However, KRT13 exhibits oncogenic functions in multiple cancers. In lung squamous cell carcinoma, KLF4 induces a KRT13+ hillock-like tumor state characterized by slower proliferation and immunomodulatory signatures 5. In breast cancer, KRT13 directly binds plakoglobin to promote c-Myc signaling, driving stemness, epithelial-mesenchymal transition, and metastasis 6. KRT13 upregulation correlates with poor prognosis and is associated with radioresistance in pancreatic cancer stem-like cells 7. KRT13 expression also serves as a diagnostic marker to differentiate lung squamous cell carcinoma from metastatic oral squamous cell carcinoma 8. These findings indicate KRT13 has dual roles: supporting normal epithelial differentiation while promoting cancer stem cell properties and metastatic potential in multiple carcinomas.