Cytokeratins (CKs) are intermediate filament proteins located in the cytoplasm. CKs belong to the most fundamental markers of epithelial differentiation; including that of the epithelia of breast ductal carcinoma, see [1].
This APP can be used to determine the tumor density i.e. the area of tumor growth compared to tissue area. With some precaution, the tumor region can be defined as the region where certain CKs are expressed in the cytoplasm.
NOTE: To get an optimal and unbiased result, the APP is dependent on a stable staining intensity.