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This biomarker is also known as:
  • cystatin-A,
  • AREI,
  • STFA,
  • Stefin-A,
  • Cystatin-AS,
  • cystatin A (stefin A),
  • STF1,
  • cystatin AS,

View in BioMuta


CSTA, or cystatin-A, is a member of the cystatin superfamily, which includes proteins that contain multiple cystatin-like sequences. Some members of the cystatin superfamily are active cysteine protease inhibitors, of which there are three families: type 1 cystatins (stefins), type 2 cystatins, and kininogens. CSTA is a stefin that functions as a cysteine protease inhibitor, forming tight complexes with papain and the cathepsins B, H, and L. Stefins have been proposed as prognostic and diagnostic biomarkers for cancer.


QA State: Curated
Type: Proteomic
Short Name:


There are no datasets associated with this biomarker.


The following organs have data associated with this biomarker…



Phase: One
QA State: Under Review


Studies have demonstrated an inverse relationship between increased cathepsin B expression and decreased CSTA in a variety of human tumors. Studies suggest that CSTA is one of the promising candidate biomarkers for lung cancer and deserves further investigation in lung tumorigenesis.

Performance Comment

CSTA belongs to a 9-member panel that provides a quantitative measure of the probability of having lung cancer that goes beyond the histological evaluation of preinvasive lesions. The identified members of the panel are TMSB4X (Thymosin beta-4), Ubiquitin, des-ubiquitin, ACBP, CSTA, Cytochrome C, and MIF.


This biomarker is currently being annotated or is under review. You must be logged in or do not have permission to view any additional information. Contact Heather Kincaid at if you should have access to this biomarker.

2016 EDRN PI Orientation

The New and Continuing EDRN Principal Investigator Orientation will take place March 14–15, 2016 in Bethesda, Maryland.

Announcement 11/05/2015

Thank you to everyone who made the 29th EDRN Steering Committee Meeting a success. The orientation for new and continuing EDRN PIs will be held Monday-Tuesday, March 14-15, 2016, on the NCI campus. More information will be available later this autumn.

Announcement 06/30/2015

A funding opportunity for a new pancreatic cancer initiative, called The Pancreatic Cancer Detection Consortium (U01), has been released. For more information, please go to /grants/guide/ pa-files/ PAR-15-289.html.