Scientists have discovered cancer’s secret weapon—a hidden hormone that shuts down immune defenses, potentially explaining why millions of patients don’t respond to current treatments.

Story Highlights

• Researchers at UT Southwestern identified SCG2 hormone that cancer cells use to disable immune system
• Discovery explains why many patients fail to respond to current immunotherapy treatments
• Blocking this hormone-receptor pathway restored immune function in animal studies
• New therapeutic target could transform cancer treatment for previously untreatable cases

Cancer’s Hidden Sabotage Mechanism Revealed

Cancer cells have been employing a sophisticated sabotage strategy that researchers only recently uncovered. Scientists at UT Southwestern Medical Center discovered that tumors secrete a previously unknown hormone called SCG2, which binds to LILRB4 receptors on immune cells called myeloids. This binding effectively switches off the body’s natural cancer-fighting capabilities, allowing tumors to grow undetected. Dr. Cheng Cheng Zhang‘s team published their findings in Nature Immunology, revealing how cancer exploits hormonal communication to survive.

A hormone that silences the immune system may unlock new cancer treatments | UT Southwestern Medical Center

Study uncovers hormone’s role in weakening body’s defenses against cancer.

Researchers at UT Southwestern Medical Center have discovered how a hormone interacts with a… pic.twitter.com/WwrUS86nBX

— Owen Gregorian (@OwenGregorian) September 23, 2025

Breakthrough Opens New Treatment Pathways

The discovery represents a paradigm shift in understanding tumor immune evasion. Unlike previously identified immune checkpoint pathways, this hormone-mediated suppression mechanism operates through an entirely different biological system. When researchers blocked the SCG2-LILRB4 interaction in animal models, they successfully restored immune function and slowed tumor growth. This breakthrough could explain why current immunotherapies only help a minority of cancer patients, as existing treatments target different pathways entirely.

Revolutionary Therapeutic Implications

The identification of this hormone-receptor axis creates unprecedented opportunities for developing new cancer treatments. Researchers are now working to develop therapeutic antibodies and small molecules that can disrupt the SCG2-LILRB4 pathway. Dr. Zhang emphasizes that understanding multiple immune evasion mechanisms is crucial for advancing cancer therapy. The discovery could benefit patients whose tumors are resistant to current immunotherapies, potentially expanding successful treatment options to previously untreatable cases.

Beyond cancer treatment, this research may have applications for autoimmune and inflammatory diseases. The dual potential presents both opportunities and challenges, as targeting immune pathways requires careful consideration of unintended consequences. However, the mechanistic understanding gained from this research provides a solid foundation for developing targeted interventions that could transform how we approach immune-related disorders across multiple medical fields.

Sources:

UT Health San Antonio scientists uncover how some cancers outsmart immune system
UT Southwestern researchers discover new immunotherapy target
A hormone that silences the immune system may unlock new cancer treatments
Researchers Uncover Cancer’s Secret Weapon Against Immune Cells
Cancer tricks the immune system with the help of hormone SCG2