Intestinal mucosal mast cells are critically involved in the development of food-induced allergic disorders. However, factors that induce differentiation of mucosal mast cells in the intestinal mucosa are largely unknown. To identify factors involved in mucosal mast cell differentiation, we compared the gene expression profiles between mucosal mast cells isolated from the small intestine and bone marrow-derived mast cells cultured in the presence of TGF-β or Notch ligand. Mucosal mast cells were isolated from the small intestine of naïve BALB/c mice by flow cytometry. Bone marrow-derived mast cells (BMMCs) were generated by culturing BALB/c bone marrow cells with murine interleukin-3 and stem cell factor for 3-4 weeks, and then cells were cultured for 6 days in the presence or absence of TGF-β or Delta-like 1 (Dll1), which is a Notch ligand. Total RNAs extracted from these cells were processed and hybridized to Affymetrix GeneChips.