Interleukin-20 receptor subunit beta（IL20RB） is a single-pass type I membrane protein and belongs to the type II cytokine receptor family. It contains 2 fibronectin type-III domains. There are two kinds of type II cytokine receptors : cytokine receptors that bind type I and type II interferons; cytokine receptors that bind members of the interleukin-10 family (interleukin-10, interleukin-20 and interleukin-22). Type II cytokine receptors are similar to type I cytokine receptors except they do not possess the signature sequence WSXWS that is characteristic of type I receptors. They are expressed on the surface of certain cells, which bind and respond to a select group of cytokines. These receptors are related predominantly by sequence similarities in their extracellular portions that are composed of tandem Ig-like domains. The intracellular domain of type II cytokine receptors is typically associated with a tyrosine kinase belonging to the Janus kinase (JAK) family.

Interleukin-10 receptor subunit beta(IL10RB), also known as Cytokine receptor class-II member 4,Cytokine receptor family 2 member 4,Interleukin-10 receptor subunit 2, belongs to the type II cytokine receptor family. IL10RB is a single- pass type I membrane protein and contains two fibronectin type-III domains. It is an accessory chain which is essential for the active interleukin 10 receptor complex. Coexpression of IL10RB and IL10RA proteins has been shown to be required for IL10-induced signal transduction. Defects in IL10RB are the cause of inflammatory bowel disease type 25 (IBD25) which is a chronic, relapsing inflammation of the gastrointestinal tract with a complex etiology.