Serum or plasma concentration of cytokeratin 7 (CK7)
This test measures the amount of cytokeratin 7, a protein found in certain cells of the body, including some cancer cells.
["Cytokeratin 7 helps identify certain types of cancer and monitor treatment response."]
Key facts at a glance
- LOINC
- 40559-7
- Short code
- CK 7 Ag Tiss Ql ImStn
- Synonyms
- CK 7 Ag Tiss Ql ImStn
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 22
- Ref high
- 198
- Critical range
- — – 10000 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- immune-stain
- CPT
- 82553
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your doctor may order this test to help diagnose or evaluate conditions such as lung cancer, breast cancer, or other cancers that may spread to the lungs. It can also be used in cases where the type of cancer is unclear or to check if cancer has returned after treatment.
What Does a High or Low Level Mean?
Elevated levels of CK7 are often associated with certain cancers, particularly those of the lung, breast, or pancreas. However, it can also be found in non-cancerous conditions like chronic lung disease. Low levels may suggest normal tissue or certain non-cancerous conditions.
Sample Collection and Preparation
This test requires a blood sample, which is typically collected by a healthcare professional through a simple vein puncture. The blood is processed into either serum (after clotting) or plasma (using an anticoagulant). The sample is then sent to a lab for analysis.
Test Process and Method
The test uses an immunoassay method to detect and quantify cytokeratin 7 in the serum or plasma. This involves antibodies that specifically bind to CK7, allowing for precise measurement of its concentration.
Reference range
Adult males: 22-198 U/L; Females: 22-198 U/LN/A
No special preparation required. Inform provider of any chest pain or symptoms.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Cytokeratin 7 is a useful biomarker for identifying certain cancers, especially when combined with other tests. It can assist in narrowing down the type of cancer, especially in cases where other tests are inconclusive. Monitoring CK7 levels over time can also help track the progression or response to treatment of certain cancers.
Short name
CK7 Level
Frequently asked questions
What Are Common Causes of Abnormal Results?
Can This Test Be Used Alongside Other Tests?
How Soon Will I Receive Results?
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 17, 2026. · Read our editorial policy