Interleukin 1 receptor-like 1(IL1RL1) is a member of the interleukin-1 receptor family, Contains 3 Ig-like C2-type domains and 1 TIR domain. It is highly expressed in kidney, lung, placenta, stomach, skeletal muscle, colon and small intestine. IL1RL1 is a receptor for interleukin-33, its stimulation recruits MYD88, IRAK1, IRAK4, and TRAF6, followed by phosphorylation of MAPK3/ERK1 and/or MAPK1/ERK2, MAPK14, and MAPK8. IL1RL1 may possibly be involved in helper T-cell function. Soluble IL1RL1 also acts as a negative regulator of Th2 cytokine production, it directly implicated in the progression of cardiac disease.