TSPO and neoplasm: While direct comparisons of PET quantification remain difficult due to lacking standardization, our in house [18F]GE-180 study in GL261 mice showed tumor SUVmean increases of only 1.1-fold over sham at week-1 and 1.4-fold at week-2 (9), indicating a distinctly lower TSPO-PET signal when compared to the early week-1 time-point of our current SB28 data (tumor vs. sham: 1.6-fold).