Although genetic engineering cannot be considered a new technology, CRISPR has taken it to a whole new level. The quickness and precision of this new biotechnology, as well as its wide range of applications, make CRISPR nothing less than a revolution. 1 The history is by now well known: the work of F. Mojica on the immune system of archaea and bacteria in the 1990s served as the basis of the development by J. Doudna and E. Charpentier in 2012, and shortly after by F. Zhang, of a gene-editing technology that emulated the bacterial immune system's ability to cut DNA with high precision. Since then, this technology has been successfully applied to all kinds of organisms, including mammals, and has been perfected and amplified not only to cut, but also to add genes. More recently, 'prime editing', developed in 2019 by David Liu and his colleagues at the Broad Institute (Cambridge, Massachusetts), seems to have reduced significantly the shortcomings of CRISPR, namely its precision, by making it 'possible to insert or delete specific sequences at genome targets with less collateral damage'. 2 Doudna and Charpentier won the Nobel Prize in 2020 for their work on CRISPR. Gene editing of humans has been controversial since the introduction of this technology. However, many have been surprised by how fast its implementation has been. In 2015, J. Huang and his Chinese team reported that they had edited human zygotes. Two years after, in 2017, K. Niakan's group in the U.K. was able to genetically modify human blastocysts. But it was in the last months of 2018 that Chinese researcher He Jiankui shocked the world when he claimed to have helped in the birth of the first genetically modified human babies, Lulu and Nana, with a third pregnancy underway. He Jiankui's experiment recruited HIV-serodiscordant couples: couples in which the man is HIV-infected, while the woman is not.The couples were informed that this procedure might make their children immune to HIV, and had their fertility treatment and pregnancy medical care paid for by the researchers. During IVF, the