Jennifer Doudna and Fyodor Urnov have founded a company that will take on the challenge of editing rare diseases, starting with phenylketonuria.

The problem is well known: many diseases are theoretically treatable by correcting the corresponding genetic defects with the help of CRISPR tools, but doing so risks being difficult or even impossible because of regulatory rigidity and economic unsustainability. The case of the first newborn treated with a bespoke therapy developed in record time (KJ Muldoon) was a splendid proof of principle. But it left many parents of children with rare diseases asking: when will it be our turn? At the same time, specialists have long been asking: will investors return to viewing gene editing as a profitable approach worth investing in?