ITGAM and familial pancreatic carcinoma: Furthermore, we analyzed different populations in the CD45+ cells, and found that CD11b+Gr1+ cells (with majority of them Ly6G+CD11b+ cells) are the most common cell type in the metastatic niche by flow cytometry analysis (Figure 5A,B) [35,36,37], suggesting that these cells may be critical for metastatic colonization of pancreatic cancer cells.