The same tissue is many chemistries at once.
Oxygen, acidity and pressure are not constants inside a tumour. They vary steeply over short distances, and each one changes what a compound does when it gets there. An average across the mass describes nowhere in it.
The blind spot
Tumour vasculature is irregular. Some regions are well perfused, some are barely reached, and the distance between the two can be under a hundred micrometres. Oxygen falls away from vessels, acidity follows it, and pressure rises where drainage is poor.
Every one of those is a chemistry change. Hypoxia alters which death pathways are available at all. Acidity changes whether a molecule crosses a membrane. Across a single mass, one compound does not behave like one compound.
What you get back
LURA carries the local conditions as part of the answer instead of averaging them away, so a result comes back split by where it holds and where it does not.
- The fraction of a mass in a state where the compound works, and the fraction where it does not
- What would have to change to move that split
- Why a candidate that won in culture underperformed in tissue — one chemistry against several
- Which conditions a programme should be screening against in the first place
The decision it changes
A single averaged number lets a project believe a compound half-works everywhere. Usually it works well in one part of the mass and not at all in another. Those are the same number and two completely different programmes.
A team that can see the split spends its time deciding which region to fix. A team holding the average spends it arguing about whether the compound works at all, and usually settles that with another year of animal work.