The Inova Health System hospital network held a grand opening ceremony Wednesday for a $150 million cancer treatment center in Fairfax County that will incorporate a patient’s genetic information in plans for treatment.

NVR founder Dwight C. Schar, shown above in 2006, donated $50 million with his wife, Martha Schar, toward the Inova Health System’s new cancer treatment center in Fairfax County. (Katherine Frey/The Washington Post)

The 420,000-square-foot Inova Schar Cancer Institute will serve as a cornerstone to the group’s new Center for Personalized Health on what was once ExxonMobil’s headquarters in Merrifield.

The 500-employee facility will begin accepting patients on May 13, hospital officials said.

Inova purchased the 117-acre site in 2015 as part of an effort to expand its “personalized medicine” operations, in which a patient’s genetic information is used to come up with a more precise diagnosis and treatment plan.

The institute is named after Dwight C. Schar, chairman of the NVR home-building company in Reston, and his wife, Martha Schar, who donated $50 million. Dwight Schar is also part owner of the Washington Redskins.