IL20RB belongs to the type II cytokine receptor family. 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. IL20RB and IL20RA form a heterodimeric receptor for interleukin-20.

> 91 % as determined by SDS-PAGE