# Scientists Discover Hidden Backup Pathway That Lets Cells Make a Key Amino Acid — and Cancer May Exploit It

*2026-09-25 14:01 UTC · Science · 1 min read*

> Montana State University researchers found a hidden cellular pathway that makes cysteine when normal systems fail — a backup route cancer cells may exploit to resist treatment.

Researchers at Montana State University, led by geneticist Ed Schmidt, have identified a previously unknown cellular survival pathway that lets mammalian cells produce cysteine even when the normal production systems fail. Cysteine is an essential amino acid cells need for basic survival and for building proteins.

The backup system works by breaking carbon-sulfur bonds in cystine, generating usable cysteine through a route scientists had not known existed. Undergraduate co-first authors Zoe Seaford and Sydney Austad, working with collaborators at the Hungarian National Institute of Oncology, helped trace the mechanism after an initial clue first surfaced in 2014 — the full nine-year effort to pin it down was published this week in Nature Chemical Biology.

While the pathway protects healthy cells, the team says cancer cells may exploit the very same backup route to survive chemotherapy, radiation, and immunotherapy. Disabling it in tumors could make existing cancer treatments more effective, opening a new angle for future combination therapies.

## Sources

- [sciencedaily.com](https://www.sciencedaily.com/releases/2026/09/260923035939.htm)

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TechTools News · https://techtools.cz/tools/news/article/2437-scientists-discover-hidden-backup-pathway-that-lets-cells-make-a-key-amino-acid
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