Scientists have already sequenced the human genome, the DNA that includes all of our thousands of genes.

But now a group of researchers are calling for an ambitious new initiative— constructing very long stretches of DNA, perhaps as much as an entire human genome.

Writing in the journal Science on Thursday, the scientists refer to the original sequencing of the genome, the Human Genome Project, as “HGP-read.” This new initiative, they propose, will be known as “HGP-write.” Instead of sequencing, it will be focused on building.

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The 25 scientists— who hail from institutions like New York University Langone Medical Center, Harvard Medical School, and the University of California— argue that synthesizing the genome is the next step in the field of genetics, and call for public conversation on the topic to discuss, among other issues, the ethics of the controversial idea.

“As human genome-scale synthesis appears increasingly feasible, a coordinated scientific effort to understand, discuss, and apply large-genome engineering technologies is timely,” the scientists write.

The biggest goal, the scientists argue, is to dramatically bring down the costs of creating, or writing, very long sections of DNA in the next decade.

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They say that the ambitious proposal could help improve human health, such as by “growing transplantable human organs,” and hope to launch this year, estimating that it could cost less than the original project to sequence the human genome.

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