CD274 and neoplasm: Our main findings are: (1) Pharmacological targeting of CSF1/CSF1R axis: (a) attenuated tumor cell proliferation and tumor-associated angiogenesis and promoted tumor cell apoptosis to limit mesothelioma progression; (b) reduced tumor immunosuppressive myeloid cells including TAMs and MDSCs, hindered CSFR1+ M2 proliferation and polarized TAMs towards M1 phenotype; (c) increased tumor infiltration by CD8 lymphocytes, CD8 lymphocyte and DC activation, reduced Tregs but stimulated the expression of PD-1/PDL1 axis components by tumor and immune cells.