During oncogenic transformation tumor cells develop mechanisms to avoid immune detection and elimination. Glioblastoma is characterized by the development of multiple immune escape mechanisms, including modulation of myeloid cells into suppressor phenotypes. Interactions between tumor glycans and C-type lectin receptors (CLR) on antigen-presenting cells play critical roles in several aspects of cancer biology. Furthermore, tumor-derived exosomes have been shown to contribute to tumorigenesis, metastasis, and immune evasion. This project aims at identifying the glycopeptide proteome of glioblastoma and glioblastoma-derived exosomes, and determining their importance in immune evasion with the ultimate goal of developing a new glycan-based immunotherapy against glioblastoma.