Other different 12 precursor proteins, namely, PGK1, ALB, VASP, PRDX5, SBSN, ACTB, CST1, AMY1B, GCA, PTMA, CFL1, and ZG16B, marked all ND GBM saliva pools, highlighting key peptides potentially linked to tumor onset and progression. This evidence concerns the gene PGK1 and glioblastoma.