CK7 is a type II cytokeratin frequently expressed in epithelial cells of the breast, ovary, endometrium, lung, and biliary tract. It is generally absent in gastrointestinal tract epithelium such as the colon. CK7 immunostaining helps define epithelial lineage and tumor origin.

Clinical utility in gynecological pathology

• Ovarian tumors: Most primary ovarian epithelial carcinomas (serous, endometrioid, clear cell) show CK7 positivity; CK7 is therefore helpful to distinguish primary ovarian carcinomas (CK7+) from metastatic colorectal carcinoma (typically CK7–/CK20+).
• Endometrial carcinoma: High CK7 expression is reported in many endometrioid and serous endometrial cancers; CK7 supports identification of Müllerian origin in metastases.
• Cervical lesions: Recent studies evaluate CK7 in HPV-related lesions (e.g., as part of epithelial differentiation panels), where CK7 patterns can correlate with squamo-columnar junction and lesion progression.

Clinical utility in breast pathology

• Primary breast carcinoma: Most ductal and lobular breast carcinomas are CK7-positive; CK7 complements breast lineage markers (ER, PR, GATA3, mammaglobin) in confirming breast origin and in evaluating metastases of unknown primary. CK7 expression is retained in the majority of breast cancer subtypes but may show variable intensity in special.

Key advantages of CE/IVD CK7 reagents for diagnostic labs

• Ready-to-use or standardized formulations validated on automated platforms (reduces inter-lab variability).
• Clinical traceability and regulatory documentation (CE-marking/IVD labeling).
• Strong literature support for CK7’s role in distinguishing Müllerian/breast primaries from gastrointestinal metastases.