IL-11 receptor is a member of the hematopoietic cytokine receptor family. This particular receptor is very similar to ciliary neurotrophic factor, since both contain an extracellular region with a 2-domain structure composed of an immunoglobulin-like domain and a cytokine receptor-like domain. Alternative splicing has been observed at this locus and two variants, each encoding a distinct isoform, have been identified. This receptor was found to be a 422-amino acid protein containing a signal peptide followed by extracellular, transmembrane, and cytoplasmic domains. The extracellular region has a 2-domain structure homologous to those of the receptors for IL6R and ciliary neurotrophic factor (CNTFR), an immunoglobulin-like domain and a cytokine receptor-like domain.