Patrick Soon-Shiong’s Culver City-based NantWorks has acquired a majority stake in Integrity Healthcare, which manages Verity Health System, adding six hospitals in California to its operation.

Soon-Shiong, a cancer doctor who was ranked No. 1 on the Business Journal’s Wealthiest Angelenos list this year with a net worth of $18 billion, will be joining Verity’s board of directors, NantWorks said in a news release.

Redwood City-based nonprofit Verity Health’s six hospitals include St. Francis Medical Center in Lynwood and St. Vincent Medical Center in Los Angeles. The company also operates Verity Physician Network and Verity Medical Foundation.

Private investment firm Blue Mountain, the founder and former majority owner of Integrity, will maintain a minority investment in Integrity. The terms of the acquisition weren’t disclosed.

“We are grateful for the ongoing support of Blue Mountain and our Verity Board of Directors and the new opportunities to collaborate with NantWorks to accelerate our revitalization efforts,” Andrei Soran, chief executive officer of Verity Health, said in a statement. “Our commitment is to revitalize our hospitals and create an integrated healthcare system that delivers better quality care.”

NantWorks is the umbrella organization for NantHealth and NantKwest, both of which are listed on the LABJ Stock Index.