TSPO and glioblastoma: In the SB-28 glioblastoma model, which also uses immunocompetent C57BL/6 mice, the magnitude of the tumoral TSPO radioligand uptake exceeds by far the inoculation-induced uptake at early time points, as recently shown [36], warranting comparative analyses on the intrinsic TSPO protein expression levels in the GL261 and SB-28 cell lines and on the potentially distinct degree of TAM infiltration in both models.