The signatories—including scientists, ethicists, and some inventors of the gene-editing tool Crisper—wrote that they do not want a permanent ban, but a period of around five years in which governments publicly declare they will not allow the clinical use of human germline editing (the editing of sperm, eggs, or embryos).

During this period, the scientists recommend discussions on the “technical, scientific, medical, societal, ethical, and moral issues” of germline editing that will lead to an international framework governing the technology. Afterward, each country can choose their own regulations.

“Nations might well choose different paths, but they would agree to proceed openly and with due respect to the opinions of humankind on an issue that will ultimately affect the entire species,” the scientists write.

To clarify, the group said they do not seek a ban on research using human sperm, eggs, and embryos, “provided that these studies do not involve the transfer of an embryo to a person’s uterus.” Nor do they seek to ban research involving non-reproductive cells to treat diseases.

Around 30 countries (including the United States) already have legislation directly or indirectly banning clinical uses of human germline editing, but this standard is not held globally. A biologist in China reportedly created the world’s first gene-edited babies last year. Despite the ethical backlash He Jiankui faced, he said he is proud of his achievement and a third baby is on the way.

Other scientists declined to sign the Nature publication, showing a divide in the community over how to best regulate inappropriate uses of gene-editing technology while also encouraging ethical research.

Dr. Jennifer Doudna, one of the inventors of Crisper, did not sign the declaration, although her co-inventor Emmanuelle Charpentier did, wrote The Wall Street Journal. According to Doudna, “it is a bit late to be calling for a moratorium,” and there could be more effective ways to prevent the implantation of edited human embryos.