Abstract: Novel polypeptide combinations, polynucleotides encoding the polypeptides, and related compositions and methods are disclosed for zcytor17-containing multimeric or heterodimer cytokine receptors that may be used as novel cytokine antagonists, and within methods for detecting ligands that stimulate the proliferation and/or development of hematopoietic, lymphoid and myeloid cells in vitro and in vivo. The present invention also includes methods for producing the multimeric or heterodimeric cytokine receptor, uses therefor and antibodies thereto.