This week, we lost a cancer research pioneer, and friend and mentor to many in the field, with the sudden death of Waun Ki Hong, M.D., a world-renowned clinical researcher who leaves behind a remarkable legacy.

He was a trail-blazing scientist whose innovations led to successful organ-sparing cancer treatment. Best known as the father of chemoprevention, his groundbreaking clinical trial at MD Anderson to treat precancerous lesions for oral cancers established proof of principle for preventing cancer by treating its precursor growths. This rapidly rippled to improve treatment for other disease sites, such as the use of tamoxifen and raloxifene to prevent breast cancer.