As the gene-editing gold rush continues, newcomer Trucode Gene Repair has a message for investors: there’s more than one way to edit a genome. The San Francisco-based start-up, which was founded in 2017, recently announced that it raised $34 million to develop a new class of gene-editing therapies that don’t rely on the bulky enzymes employed in CRISPR gene editing. Instead, the start-up is using synthetic molecules called peptide nucleic acids (PNAs). PNAs impersonate and bind to DNA. In PNAs, the phosphodiester backbone that connects the bases of DNA is replaced with a polyamide backbone, which makes the synthetic strand less susceptible to degradation. In 2002, Yale University geneticist Peter Glazer showed that PNAs could be used to guide a short strand of synthetic DNA to a particular mutation in the genome. Once there, the PNA occasionally coaxes the cell’s natural repair machinery to swap in the new DNA strand