In the comparisons of the sequential GBM pairs, the IHC evaluations showed significantly higher expressions of ADRBK1 (75 (85–30) vs. 40 (75–20)) (p = 0.011) and DRD2 (70 (80–40) vs. 40 (60–20)) (p = 0.026) in GBM1 compared to GBM2, respectively. Here, DRD2 is linked to glioblastoma.