Introducing new genes into plants requires a promoter specific to the area where the gene is to be expressed.
The most promising technique is to introduce pest-resistant genes into crop plants.
In Gelsinger's case, the goal was to introduce therapeutic genes into his liver cells.
But scientists have still not been able to introduce new genes reliably into important grain crops like corn and wheat.
"This is meant to pave the way to introducing genes that can improve the survival of cancer patients."
Humans have participated directly in 'creating' new species by introducing genes to existing genotypes.
This can introduce genes into a population that were not present before.
This year scientists at three different companies said they had introduced genes into corn.
Furthermore, until now, breeders were never able to introduce genes from one species into another or to make such extensive changes.
But so far, almost all attempts to introduce curative genes into patients have fizzled.