Jacob Kimmel

So there are canonical examples where you can seemingly reverse the age of a cell, for instance, at the level of a transcriptome, but simultaneously you might be changing that cell's type or identity.

So Shinya Monaka, a scientist who won the Nobel in 2012 for some work he did in about 2007, discovered that you can just take four transcription factors and actually just by turning on these four genes, turn an adult cell all the way back into a young embryonic stem cell.

This is a pretty amazing existence proof that shows that you can reprogram a cell's type and a cell's age simultaneously just by turning on four genes.

Out of the 20,000 genes in the genome, the tens of millions of biomolecular interactions, just four genes is enough.

That's a shocking fact.

And so we actually have known for many years now that you can reprogram the age of a cell.

The challenge is that simultaneously you're doing a bunch of other stuff, as you alluded to.

You're changing its type.

And that might be pathological.

If you did that in the body, it would probably cause a type of tumor called a teratoma.

So we measure not only at the level of the genes a cell is using.

Do you still look like the right type of cell?

Are you still a hepatocyte?

Are you still a T cell?

If not, that's probably pathological.

But you can also use that same information to check for a number of other pathologies that might develop.

Did I make this T cell hyperinflammatory in a way that would be bad?

Did I make this liver cell potentially neoplastic, proliferate too much even when the organism's healthy and undamaged?

And you can check for each of those at the level of gene expression programs and then likewise functionally.

Before you put these molecules in a human, you actually just functionally check in an animal.