The IL-28RA, also known as IFNLR1, CRF-2-12, and LICR2, is a 57kD single-pass type I membrane glycoprotein containing one fibronectin III domain. Widely expressed in many tissue types, IL-28RA and IL-10RB dimerize to form the class II cytokine receptor for IL-28A (IFNlambda2), IL-28B (IFNlambda1) and IL-29 (IFNlambda3), also known as the type III interferons. Like type I interferons, the type III interferons have been shown to activate the Jak-STAT and MAPK signalling pathways and exhibit antiviral activity.