This protein binds to interleukin-12 (IL-12) with a low affinity, and is part of the IL-12 receptor complex.

The coexpression of this and IL-12Rβ2 protein was shown to lead to the formation of high-affinity IL-12 binding sites and reconstitution of IL-12 dependent signaling.

This complex forms a disulfide-linked oligomer, which is required for its IL-23 binding activity.

Various mutations in this gene were found to result in the immunodeficiency of patients with severe mycobacterial and Salmonella infections.

[6] Two alternatively spliced transcript variants of this gene encoding distinct isoforms have been reported.