The pioneering studies of Dr. Larry Keefer and colleagues with diazeniumdiolates or NONOates as a platform have unraveled the chemical biology of many nitric oxides and have led to the design of a variety of promising therapeutic agents in oncology, gastroenterology, antimicrobials, wound healing, and the like. This dedication to Dr. Larry Keefer briefly highlights some of his studies using the diazeniumdiolate platform in the cancer arena.