11. Histamine is a small molecule, stored in granules of mast cells and basophils. 12. The cells involved are macrophages, mast cells , fibroblasts, and plasma cells. 13. Mast cells have antibodies on their surface called immunoglobulin E ( IgE ).14. Biopsies on the bladder walls of people with IC usually contain mast cells . 15. Possible candidates include mast cells , known to facilitate the inflammatory response. 16. The site an immature mast cell settles in probably determines its precise characteristics. 17. Expression of some molecules may change in course of the mast cell activation. 18. The mast cell , another granulocyte, is similar in appearance and function. 19. :Once released, these neuropeptides induce the release of histamine from adjacent mast cells . 20. Mast cell tumors do not necessarily follow the histological prognosis.