SIRT2 and neoplasm: Static images of 12-[18F]DDAHA accumulation/retention (SUV) obtained between 15 and 20 min post i.v. injection with highest tumor-to-normal brain and tumor-to-muscle SUV ratios may provide more specific images of SIRT2 expression-activity in target tissues, if defluorination would be minimized in the next generation of radiotracers.