PDCD1LG2 and glioblastoma: On Spearman’s correlation analysis, significant positive correlations were found between the expression of FAT1 and expression of immunosuppressive markers PD-L1 (r = 0.236, p = 0.053) and PD-L2 (r = 0.244, p = 0.048) in the studied GBM samples (Figures 6D–F).