TREM2 and glioblastoma: Analysing TAM markers in the leading edge of the tumours revealed high CD32a, TREM2 or PD-L1 was associated with poorer overall survival of glioblastoma patients (log-rank test P = 0.020, 0.028, 0.034, respectively, for the top quartile versus lower quartiles of each marker; Fig. 4).