A FEW years ago, molecular biologists made a breakthrough. By borrowing an antiviral mechanism called CRISPR-Cas9 from bacteria, they created an easy way to tweak the genetic information in a cell’s nucleus. This has implications for medicine and agriculture. Unfortunately, a dispute over who invented what parts of the technique first has threatened to curtail this potential. But that may not matter, for CRISPR-Cas9 turns out not to be the only way bacteria protect themselves from the attentions of viruses. In the latest edition of Cell, a group of researchers led by Feng Zhang of the Broad Institute in Cambridge, Massachusetts (who is one of the parties to the patent dispute), have announced their discovery of another such mechanism. Indeed, first indications suggest it may be even better than CRISPR-Cas9.

Like it, this mechanism, CRISPR-Cpf1, could become a tool that can deal with intractable genetic illnesses such as Huntington’s, and degenerative conditions such as Alzheimer’s. It might also be used to produce new classes of antiviral treatment, and thus curb infectious disease. Plant and animal breeders may find it useful, too, for creating new strains of crops and livestock. Indeed, because, like CRISPR-Cas9, it does not involve taking genes from one organism and implanting them in another, it will not count as “transgenic”, a bugaboo of campaigners and customers alike.

CRISPR-Cas9 consists of a pair of enzymatic “scissors” (the Cas9) and a guide sequence of DNA (the CRISPR) that tells the scissors where to cut. The dispute over inventorship has caused some, though not all, potentially interested companies to give the technology a wide berth. Monsanto, a plant-breeding and agrochemicals firm, has gone on record as saying that it is reluctant to employ CRISPR-Cas9 widely until it understands the intellectual property concerned. Drug companies have also circled at a distance. CRISPR-Cpf1, which uses a different pair of scissors, may not suffer from these legal problems.

CRISPR-Cpf1 may be better than CRISPR-Cas9 in another way, too. Cpf1 is a smaller and simpler enzyme (known technically as an endonuclease) than Cas9. That means it will be easier to deliver to the cells whose genes need modifying.