Abstract: The present invention provides a properly folded steroidogenic factor-1 (SF-1)-like receptor variant, or active fragment thereof, which has an amino acid sequence that encodes a SF-1-like receptor or an active fragment thereof and that lacks at least one naturally occurring cysteine residue within the ligand-binding domain of the receptor. Such a properly folded SF-1 receptor variant or active fragment thereof can exhibit increased monomer stability as compared to analogous receptor retaining the cysteine residues lacking in the variant. In one embodiment, at least one naturally occurring cysteine residue within the ligand-binding domain of the SF-1-like receptor is substituted with a non-cysteine residue such as serine or threonine.