An interleukin receptor subunit that was originally discovered as a component of the INTERLEUKIN 2 RECEPTOR. It was subsequently found to be a component of several other receptors including the INTERLEUKIN 4 RECEPTOR, the INTERLEUKIN 7 RECEPTOR, the interleukin-9 RECEPTOR, the interleukin-15 RECEPTOR, and the INTERLEUKIN-21 RECEPTOR. Mutations in the gene for the interleukin receptor common gamma chain have been associated with x-linked combined immunodeficiency diseases.