Myeloid cells are required for PD-1/PD-L1 checkpoint activation and the establishment of an immunosuppressive environment in pancreatic cancer

Our results show that myeloid cells support immune evasion in pancreatic cancer through EGFR/MAPK-dependent regulation of PD-L1 expression on tumour cells. Derailing this crosstalk between myeloid cells and tumour cells is sufficient to restore anti-tumour immunity mediated by CD8⁺ T cells, a finding with implications for the design of immune therapies for pancreatic cancer.