Former Vice President Joe Biden made a campaign promise to “cure” cancer if elected president in 2020 during an event in the state of Iowa on Monday afternoon.

“I’ve worked so hard in my career, that I promise you, if I’m elected president you’re gonna see the single most important thing that changes America, we’re gonna cure cancer,” Biden told supporters in Ottumwa.

Biden has made eradicating the deadly disease a primary focus since his son, Beau Biden, lost his fight in 2015 with Glioblastoma, an aggressive form of brain cancer. While vice president, he oversaw the Obama administration’s “Cancer Moonshot” — an initiative aimed at achieving a “decade’s worth of advances in cancer prevention, diagnosis, and treatment, in five years.”

After leaving the White House, Biden oversaw the Biden Cancer Initiative with a mission to “develop and drive implementation of solutions to accelerate progress in cancer prevention, detection, diagnosis, research, and care, and to reduce disparities in cancer outcomes.”

He is no longer a part of the initiative since running for president.