ROCHESTER, Minn. (AP) — The Mayo Clinic says it has received its largest gift ever from a living individual.

Mayo officials announced Thursday that patient and philanthropist Richard O. Jacobson is contributing $100 million that will be used to help establish the clinic’s proton beam therapy program. The program will include new facilities on Mayo’s Rochester and Phoenix campuses. The $200 million Rochester facility will be named in Jacobson’s honor.

Mayo says proton beam therapy is an advance over traditional radiation therapy for some cancers because it’s more precisely targeted, allowing for higher doses with fewer adverse effects.

Jacobson is the founder of Jacobson Companies, headquartered in Des Moines, Iowa. It’s one of the largest privately-owned warehouse companies in the United States. He says he began coming to the Mayo Clinic as a child.