Researchers Discover New Target for Antibody Cancer Drugs

UCSF team finds cancer-causing enzyme SRC on tumor cell surfaces, enabling new immunotherapy approaches.

Mar. 13, 2026 at 5:09am by Ben Kaplan

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Researchers at the University of California, San Francisco (UCSF) have discovered that the cancer-causing enzyme SRC, previously thought to only exist inside cells, also appears on the surface of certain tumor cells. This unexpected finding allows scientists to target SRC with antibody-based therapies that can deliver radioactive payloads or summon immune cells to kill the cancer cells. The new target could apply to up to half of all tumors.

Why it matters

The discovery of SRC on the surface of tumor cells represents a major breakthrough, as previous attempts to block SRC with drugs have been limited by the fact that the enzyme is also needed in healthy cells. Targeting SRC on the cell surface with antibody therapies could provide a more selective and effective way to treat a wide range of cancers.

The details

The UCSF researchers found that as cancer cells rapidly divide, they produce a lot of cellular waste that overwhelms the cells' normal recycling system. Instead of being broken down, some of this waste is expelled from the cells, carrying the SRC enzyme to the cell surface where it acts as a "red flag" that can be targeted by antibody therapies. The team developed experimental antibodies that were able to accumulate in human tumor cells implanted in mice and help immune cells recognize and kill the cancer cells.

  • The discovery of SRC on the tumor cell surface was made by UCSF researchers in 2026.
  • The findings were published in the journal Science on March 12, 2026.

The players

Jim Wells

Professor of Pharmaceutical Chemistry at UCSF and senior author of the paper.

Corleone Delaveris

First author of the paper, who did the work as a post-doctoral researcher in Wells' lab and is now at Inversion Therapeutics.

Michael Evans

Professor of Radiology at UCSF and collaborator on the research.

Inversion Therapeutics

A company that has licensed the antibodies and related molecules from UCSF to explore their therapeutic potential.

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What they’re saying

“No one thought to look for it on the outside, said Jim Wells , PhD, professor of Pharmaceutical Chemistry at UCSF and senior author of the paper, which appears in Science on March 12. "Our discovery enables us to test proven immunotherapies on this new tumor target.”

— Jim Wells, Professor of Pharmaceutical Chemistry at UCSF (Science)

“We saw that SRC was getting swept out onto the outer membrane, where it sat exposed like a red flag," said Corleone Delaveris, PhD, first author of the paper, who did the work as a post-doctoral researcher in Wells' lab and is now at Inversion Therapeutics.”

— Corleone Delaveris, First author of the paper (Science)

What’s next

UCSF has licensed the antibodies and related molecules to Inversion Therapeutics to explore their therapeutic potential.

The takeaway

The discovery of SRC on the surface of tumor cells represents a major breakthrough in cancer research, as it enables the development of more targeted and effective antibody-based therapies that can selectively kill cancer cells while leaving healthy cells unharmed.