A stepwise logistic regression further refined this list to five putative uEV biomarker proteins (KRT19, RPS2, RPL18, RPL28, RPL7A) that had significantly higher levels in GBM Pre-OP samples relative to HC (Fig. 2f-1), with an excellent accumulative diagnostic performance of 95.8% (AUC = 0.958; Fig. 2f-2). Here, KRT19 is linked to glioblastoma.