In search for novel non-invasive GBM biomarkers we applied the PEPperPRINT® technology and designed customized printed peptide arrays covering the complete linear amino acid sequence of six known tumor-associated antigens (EGFR [18], TNC [19], GLEA2 [22, 23], MAGEA3 [21], PHF3 [23, 24], FABP5 [20]; Figure 1B, data supplement). The gene discussed is PHF20; the disease is glioblastoma.