Mast cells migrate to the mucosal epithelium during intestinal nematode infections in mice, where they express abundant mucosal mast cell‐specific proteases, mouse mast cell protease‐1 and ‐2 (MCPT1 and MCPT2). Expression of these proteases is strictly controlled by transforming growth factor‐β₁ (TGF‐β₁) in the epithelium. In vitro homologues of mucosal mast cells are generated by culturing bone marrow‐derived mast cells (BMMC) in the presence of TGF‐β₁. We examined the proteome of BMMC cultured either in the presence of TGF‐β₁ (n = 5) or of a neutralising anti‐TGF‐β₁ antibody (n = 5). Cell extracts were examined by 2‐DE, and changes in expression levels of protein spots were determined by densitometry. Spots of interest were identified by tryptic peptide mapping. In addition to the up‐regulation of MCPT1 and MCPT2, which accounted for approximately 40% of all soluble protein in the TGF‐β₁ treated cells, MCPT7 was modestly up‐regulated by TGF‐β₁, and calnexin was up‐regulated fivefold. A 7.6‐fold down‐regulation of galectin‐1 was verified by Western blotting and FACS analysis. Galectin‐1 is located on the cell surface where it mediates cellular adhesion to basement membranes. Regulation of its expression by TGF‐β₁ may be of relevance to mast cell adhesion within the epithelium.