Interleukin-12 receptor beta 2 (IL12RB2) is a type I transmembrane protein with a 595-amino-acid-long extracellular domain and a cytoplasmic tail of 216 amino acids that contains three tyrosine residues. It binds Interleukin-12 with low affinity. IL12RB2 binds Interleukin 12 receptor beta 1 subunit (IL12RB1) forming the high affinity Interleukin-12 receptor (Presky et al. 1996a, 1996b), which signals via JAK2 and TYK2 (Zou et al. 1997).