These correlation analyses further supported that MHC-II+/BST2+ Macrophages, CD43−IgD+ mature B cells, and cDCs might contribute to anti-tumor immunity, whereas Arg-1+ Macrophages, CD43+IgD− immature B cells, MDSCs, and Tregs may have immunosuppressive effects in PDAC. The gene discussed is ARG1; the disease is neoplasm.