Relative to Post-OP levels, 64 uEV proteins changed significantly at GBM tumour recurrence (p ≤ 0.05; Fig. 3b, Supplementary Table 5), including three proteins (GGH, GRN, ITM2B) that increased by ≥2-fold in the REC group (adjust p-val≤0.05; Fig. 4b). Here, GRN is linked to neoplasm.