STAT3 and glioblastoma: A potential site of interaction between miR-21-5p and STAT3 and PDCD4 was identified in the 3’UTR (upper panel, Figure 4A); more importantly, based on TCGA database, a strong negative correlation between the expression level of PDCD4 and miR-21-5p was established within a cohort of GBM patients (n = 525, lower panel, Figure 4B).