5-ALA Assisted Surgery of Human Glioblastoma Samples Reveals an Enrichment of T Cells Expressing PD-1 and CD103 in the Intermediate and Marginal Layers.

Glioblastoma is the most common malignant brain tumor in adults, for which immunotherapy shows reduced efficacy. Current knowledge on immunotherapy failure is limited and detailed information about immune infiltrates in glioblastoma is urgently needed. We enrolled 34 glioblastoma patients collecting peripheral blood (PB), total tumor resection, or tumor from the necrotic area, the intermediate, and the marginal tissue through 5-aminolevulinic-acid (5-ALA) assisted surgery.