GitLab's founder went 'Founder Mode' on cancer — and it worked

When standard chemo, surgery, and radiation couldn't stop his osteosarcoma, GitLab co-founder Sid Sijbrandij built a personalized cancer-fighting stack. He uploaded RNA sequencing data into ChatGPT to identify overexpressed gene pathways, coordinated whole-genome sequencing (~$500), and used single-cell analysis via 10x Genomics to model his tumor.

The result: experimental FAP-targeting radioligand therapy in Germany, a personalized neoantigen mRNA vaccine, and CAR-T therapies in development. After treatment, T cells in his tumor jumped from 19% to 89%. By January 2026, scans showed no evidence of disease.

He's now founding a company to make this personalized medicine approach accessible beyond the wealthy — starting with affordable sequencing to replicate what he did.

Why it matters: This is a real-world proof-of-concept that AI-assisted medical reasoning can surface treatment paths that standard oncology misses — and it's moving from one founder's story toward a replicable model.