Fred Hutch President and Director Dr. Gary Gilliland greets Madame Peng Liyuan, the wife of Chinese President Xi Jinping at the Fred Hutch campus in Seattle, Wash. on Sept. 23, 2015.

Madame Peng Liyuan, the wife of Chinese President Xi Jinping, speaks with Fred Hutch President and Director Dr. Gary Gilliland and Bill Gates at Fred Hutchinson Cancer Research Center in Seattle, Wash. on Sept. 23, 2015. She visited the cancer research center while her husband toured other locations in Seattle and Tacoma, Wash. They continue on to meet with President Obama later this week.

Fred Hutch President and Director Dr. Gary Gilliland greets Madame Peng Liyuan, the wife of Chinese President Xi Jinping at the Fred Hutch campus in Seattle, Wash. on Sept. 23, 2015.

Fred Hutch President and Director Dr. Gary Gilliland greets Madame Peng Liyuan, the wife of Chinese President Xi Jinping at the Fred Hutch campus in Seattle, Wash. on Sept. 23, 2015.

Fred Hutch President and Director Dr. Gary Gilliland gives Madame Peng Liyuan, the wife of Chinese President Xi Jinping, a tour of HIV research labs at the Fred Hutchinson Cancer Research Center in Seattle, Wash. on Sept. 23, 2015.

Madame Peng Liyuan, wife of the Chinese President, and Fred Hutch President and Director Dr. Gary Gilliland listen to Dr. Jonathan Bricker speak about his smoking sessation program during his visit to the Fred Hutch campus in Seattle, Wash. on Sept. 23, 2015.

Melinda Gates speaks with Madame Peng Liyuan, the wife of Chinese President Xi Jinping, during a visit to the Fred Hutchinson Cancer Research Center in Seattle, Wash. on Sept. 23, 2015.

Dr. Steve Self, Dr. Julie McElrath, Dr. Gary Gilliland, Madame Peng Liyuan, Mr. Bill Gats, Ms. Melinda Gates and Dr. Lena Yao pose for a group photo at the Fred Hutchinson Cancer Research Center in Seattle, Wash. on Sept. 23, 2015.

Peng Liyuan, center, the wife of Chinese President Xi Jinping, tours a H.I.V. vaccine research lab at the Fred Hutchison Cancer Research Center, with Julie McElrath, right, director of the vaccine and infectious disease division, and center President Gary Gilliland, left, Wednesday, Sept. 23, 2015, in Seattle. (AP Photo/Ted S. Warren)

Peng Liyuan, right, the wife of Chinese President Xi Jinping, stands with Bill Gates, left, of the Gates Foundation, as they tour the Fred Hutchison Cancer Research Center, Wednesday, Sept. 23, 2015, in Seattle. (AP Photo/Ted S. Warren)

Peng Liyuan, left, the wife of Chinese President Xi Jinping, speaks at the Fred Hutchison Cancer Research Center as she sits with center president Gary Gilliland, right, Wednesday, Sept. 23, 2015, in Seattle. (AP Photo/Ted S. Warren)

Yiming Shao, the the chief expert on AIDS at the Chinese Center for Disease Control and Prevention, speaks during a visit by Peng Liyuan, the wife of Chinese President Xi Jinping, to the Fred Hutchison Cancer Research Center, Wednesday, Sept. 23, 2015, in Seattle. (AP Photo/Ted S. Warren)

Peng Liyuan, the wife of Chinese President Xi Jinping, smiles as she listens to presentations during a visit to the Fred Hutchison Cancer Research Center, Wednesday, Sept. 23, 2015, in Seattle. Xi and his wife were in Seattle on their way to Washington, D.C., for a White House state dinner on Friday. (AP Photo/Ted S. Warren)

Peng Liyuan, second from left, the wife of Chinese President Xi Jinping, poses for a photo with Gary Gilliland, left, president of the Fred Hutchison Cancer Research Center, and Bill and Melinda Gates of the Gates Foundation, during a tour of the center, Wednesday, Sept. 23, 2015, in Seattle. (AP Photo/Ted S. Warren)

Peng Liyuan, right, the wife of Chinese President Xi Jinping, walks with Melinda Gates, left, of the Gates Foundation, as they tour the Fred Hutchison Cancer Research Center, Wednesday, Sept. 23, 2015, in Seattle. Xi and his wife were in Seattle on their way to Washington, D.C., for a White House state dinner on Friday. (AP Photo/Ted S. Warren)