The levels of these cells, phenotypically characterized in the mouse by CD11b and Gr1 markers [18]–[20], are increased in the pancreas, lymph nodes, liver and spleen of pancreatic cancer bearing mice [21]–[26], but only in the spleen (not the pancreas) of mice bearing the pancreatic cancer precursor lesion PanIN [21]. The gene discussed is ITGAM; the disease is familial pancreatic carcinoma.