Jennifer Doudna, a microbiologist at the University of California, Berkeley and one of the co-authors of ground-breaking research on gene editing, isn’t totally comfortable with her discovery.

“I could scarcely begin to conceive of all the ways in which our hard work might be perverted,” Doudna wrote in her new book, A Crack in Creation: Gene Editing and the Unthinkable Power to Control Evolution, which comes out later this month. “Had I created a monster?”

Doudna is credited with pioneering a precise gene editing technique known as CRISPR-Cas9, which allows for the precise editing of genes. The technique could theoretically be used to eliminate diseases like Huntington’s, create produce that stays fresh longer, and engineer animals to better serve as human organ donors. It could also theoretically be used to create “designer babies” — hyperintelligent, disease-free, super-strong genetic marvels.

This eugenics aspect is what frightens Doudna, who also said she has had dreams about Hitler appearing in a pig mask. Gene editing could save lives, but it also presents ethical problems that could worsen inequality around the world.