A surgeon performs a robot-assisted prostate tumorectomy using ultrasound imaging at the Edouard Herriot hospital in Lyon, France in 2014. AFP PHOTO / JEFF PACHOUDJEFF PACHOUD/AFP/Getty Images

President Obama will welcome 170 people to the White House Thursday for a summit on his precision medicine initiative, the  year-old effort to treat and prevent disease based on individual differences in genetics, environment and lifestyle.

The president will participate in a panel discussion on advances that have been made since he announced the initiative during his 2015 State of the Union address. That includes the National Institutes of Health's project to recruit 1 million volunteers for a nation-wide research project by 2019. By studying the genes and health habits of those volunteers, the NIH hopes to learn the genetic commonalities for a range of diseases, individual differences in responses to drugs and a range of other information not available via smaller studies.

In a briefing with reporters Thursday, NIH Director Francis S. Collins called the effort "the largest, most ambitious research project of this sort ever undertaken." Responsibility for assembling the volunteers has been awarded to Vanderbilt University and advisers from Verily (formerly Google Life Sciences), Collins said. The NIH hopes to enroll 79,000 people this year, Collins said.

John P. Holdren, director of the White House Office of Science and Technology Policy, noted that NIH already is expanding the number of clinical trials aimed at discovering genetic causes of cancer.

More than 40 private, non-profit and public groups will announce plans to accelerate the pace of the initiative, according to a White House news release.