SPP1 and pancreatic neoplasm: To validate the association of M2-macrophages with EndoMT cells-involved PDAC, C57BL/6 mice were subcutaneously inoculated with mouse pancreatic cancer Panc 02 cells together with mouse enodothelial cells (3B-11 cells) or EndoMT cells (OPN-treated 3B-11 cells, Additional file 2: Fig. S1).