The protein encoded by this gene is a member of the interleukin 1 receptor family. Studies of the similar gene in mouse suggested that this receptor can be induced by proinflammatory stimuli, and may be involved in the function of helper T cells. This gene, interleukin 1 receptor, type I (IL1R1), interleukin 1 receptor, type II (IL1R2) and interleukin 1 receptor-like 2 (IL1RL2) form a cytokine receptor gene cluster in a region mapped to chromosome 2q12. Alternative splicing of this gene results in multiple transcript variants. Highly expressed in kidney, lung, placenta, stomach, skeletal muscle, colon and small intestine. Isoform A is prevalently expressed in the lung, testis, placenta, stomach and colon. Isoform B is more abundant in the brain, kidney and the liver. Isoform C is not detected in brain, heart, liver, kidney and skeletal muscle. Expressed on T-cells in fibrotic liver; at protein level. Overexpressed in fibrotic and cirrhotic liver.