"MAGED1 binds and positively regulates the transcriptional activity of family members SIM1 SIM2 NPAS4 and ARNT2 but does not interact with AhR HIF1alpha and ARNT. This interaction is mediated by PAS repeat regions which also form the interface for bHLH PAS dimerisation and accordingly MAGED1 is not found in complex with bHLH PAS dimers."xsd:string