TSPO and neoplasm: A regression model using contralateral TSPO-PET signals as outcome variable and mean tumor TSPO-PET signals as well as tumor TSPO-PET volumes as predictors revealed significant associations of both TSPO-PET-dependent variables (tumor SUVrmean: β = 0.624, P < 0.0001; tumor TSPO-PET volume: β = 0.251, P = 0.044), together accounting for 55% of the variance in contralateral TSPO-PET signals of patients with glioblastoma (F(2,35) = 23.34, P < 0.0001, R2 = 0.571, R2Adjusted = 0.547).