Extended Data Fig. 1. Prominent infiltration of myeloid immunosuppressive cells in iKRAS tumors.

A. PDAC tumor development in syngeneic mouse model with representative images of tumor detected by bioluminescence, PET/CT and MRI at indicated timepoints. B. Tumor volume measured by MRI at indicated timepoints (top) and Kaplan-Meier curve depicting overall survival (bottom) for untreated iKRAS tumor bearing mice (n=10 mice). C. Representative images of normal pancreas, orthotopic and autochthonous (GEMM) iKRAS tumors with H&E, Masson Trichrome, smooth muscle actin (SMA) and vimentin staining. Scale bars: 100μm. D. Representative H&E images of iKRAS tumors invading into adjacent lymph nodes (left=4x magnification, right=20x magnification). E. Representative coronal and axial MRI images of iKRAS tumor invading into duodenum. F. Representative images of normal pancreas and human PDAC tumors with SMA, Vimentin and CD45 staining. Scale bars: 100μm. Red arrow indicates positively stained cells. G. Percentage of granulocytic (CD45⁺CD11b⁺Ly6G⁺Ly6C^-) and monocytic MDSCs (CD45⁺CD11b⁺Ly6G^-Ly6C⁺) within syngeneic iKRAS tumors (n=10 tumors) assessed by CyTOF at 4 weeks after initial tumor detection. Two-sided Student’s t-test. H. Representative images (bottom) of normal pancreas, orthotopic and autochthonous (GEMM) iKRAS tumors with indicated staining. n=6 biological replicates. Scale bars: 100μm. The bar graph (top) shows quantification of each cell type as analyzed by IHC. Two-sided Student’s t-test. I. Representative images of normal pancreas and orthotopic iKRAS tumors with indicated staining. Scale bars: 100μm. J. Percentage of Treg (CD45⁺CD3⁺TCRβ⁺CD4⁺FoxP3⁺) among CD4⁺ T cells within syngeneic iKRAS tumors (n=10 tumors) assessed by CyTOF at 4 weeks after initial tumor detection. Two-sided Student’s t-test. K. Representative images of normal pancreas and human PDAC tumors with indicated staining. Scale bars: 100μm. Red arrow indicates positively stained cells. Data in G, H and J are presented as mean ± s.e.m.