Although elevation of producing proteins, such as tumour necrosis factor (TNF), interleukin-1β (IL-1β) and interleukin-6 (IL-6) has been described during the third phase of intestinal mucositis (signaling and amplification) [4], [5], our data suggest that MTX-induced mucositis was accompanied by a decreased levels of IL-1B protein levels. Here, IL1B is linked to mucositis.