# Claude Sonnet 5 chose a gene therapy and operated on a mouse brain without human decisions

> Original title: A Claude model autonomously chose a gene therapy and operated on a mouse brain with no human decision-making

- Source: The Decoder
- Published: 2026-10-30T19:42:59.000Z
- Bad Influence: https://badinfluence.news/items/mhslp2wqs1is6wljtbfstft7b
- Original: https://the-decoder.com/a-claude-model-autonomously-chose-a-gene-therapy-and-operated-on-a-mouse-brain-with-no-human-decision-making/

## Summary

Exin Therapeutics CEO Gabriel Ocana-Santero says a Claude Sonnet 5 agent selected a drug, brain target and coordinates, then performed an injection in an epilepsy mouse model. The agent refused to continue when its target fell outside the device's range of motion, and Ocana-Santero fixed the code by hand. The results have not been peer-reviewed, and a technical report is expected.

## Why it matters

The article shows how an agent's refusal during a live procedure exposed the tension between autonomy and safety guardrails in lab automation.