[echelon]

> A long time ago in a place far far away, I was part of a team that did exactly this to differentiate between healthy and possibly pre-cancerous tissue.

How did those techniques pan out? Did patients ingest fluorescent dyes that got ingested and metabolized faster by cancerous cells, or do some types of cancer cells naturally fluoresce with a unique spectra you can detect?

Epithelial and endothelial cells only?