Since we have previously shown the deleterious role of IL–18 in the pathogenesis of irinotecan-induced intestinal mucositis [15] and considering that MyD88 is the key signaling molecule downstream of several TLRs and members of the interleukin–1 receptor superfamily [39], we investigated whether this adaptor protein is involved in the pathogenesis of mucositis. The gene discussed is IL18; the disease is mucositis.