French and American scientists won the 2020 Nobel Prize in Chemistry Wednesday for developing a tool that can change the genetic material of living things. Emmanuelle Charpentier of France and American Jennifer Doudna developed the genetic tool known as CRISPR-cas9. The tool has been described as “molecular scissors” which can change nucleic acids, such as DNA, which hold the genetic information necessary for life. The 2020 chemistry prize marks only the fourth time that a Nobel in the sciences was awarded exclusively to women. Female researchers have long received less recognition for their work than men in the prize’s 119-year history. The Swedish Academy of Sciences said Charpentier and Doudna’s discovery has helped provide new treatments for cancer. It also might supply a way to cure diseases passed down through generations. But the tool also raises some ethical concerns.