For the first time, scientists have sequenced a complete human genome, a landmark feat that will help researchers better understand how DNA is different from person to person and the role genetics play in disease.

The research was published Thursday in the journal Science. In 2003, the Human Genome Project announced it had sequenced 92 percent of the human genome, and over the last two decades, a team of nearly 100 scientists has worked to fully reveal the remaining 8 percent.

“Having this complete information will allow us to better understand how we form as an individual organism and how we vary not just between other humans but other species,” research leder Evan Eichler of the University of Washington told CNN.

The newly uncovered genes are highly complex. Because the DNA regions have multiple repetitions, it was difficult to string the DNA together in the right order using previous sequencing techniques, CNN says. In the last 10 years, two new DNA sequencing technologies were developed that allowed researchers to sequence up to 1 million DNA letters at once, with some mistakes, and 20,000 letters with 99.9 percent accuracy.

Eichler said the researchers found that “these genes are are incredibly important for adaptation. They contain immune response genes that help us to adapt and survive infections and plagues and viruses. They contain genes that are … very important in terms of predicting drug response.” Read more at CNN.