Utilize the input text as a context reference, choose the right relationship between Columbia University and Columbia University Medical Center from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

He joins us from Columbia University Medical Center where he most recently served as Professor of Medicine and Experimental Therapeutics and the Director of the Center for Lymphoid Malignancies, as well as co-Program Director of the Lymphoid Development and Malignancy Program at the Herbert Irving Comprehensive Cancer Center at Columbia University Medical Center.

Answer: subsidiary