Minor trauma from daily activities such as swallowing and chewing can cause ulceration; (d) Ulceration / bacteriological phase if neutropenia is suspected to occur bacterial colonization of the ulcer so that in the mucosal tissue there are many endotoxins and the subsequent release of IL-1 and TNF-alpha; (e) The healing phase in which re-epithelialization occurs in the ulcer (Sonis, 2004). Here, TNF is linked to ulcer disease.