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This biomarker is also known as:
  • TMSB4,
  • T beta-4,
  • TB4X,
  • thymosin β4,
  • FX,
  • prothymosin beta-4,
  • Fx,
  • thymosin, beta 4, X chromosome,
  • thymosin beta-4,
  • THYB4,
  • PTMB4,
  • thymosin beta 4, X-linked,

View in BioMuta


TMSB4X, or thymosin beta-4, belongs to the thymosin beta family. It is an actin sequestering protein which plays an important role in the regulation of actin polymerization. TMSB4X binds to and sequesters actin monomers (G actin) and therefore inhibits actin polymerization. It is also involved in cell proliferation, migration, and differentiation. This gene escapes X inactivation and has a homolog on chromosome Y.


QA State: Curated
Type: Protein
Short Name:


There are no datasets associated with this biomarker.


The following organs have data associated with this biomarker…



Phase: Two
QA State: Under Review


Overexpression of thymosin beta-4 in tumors has been suggested to stimulate lung tumor metastasis by activating cell migration and angiogenesis. The gene expression of thymosin beta-4 was also significantly associated with metastasis in NSCLC patients and it was suggested as a prognostic parameter for NSCLC.

Performance Comment

Thymosin beta-4 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.