A regulatory factor X transcription factor that is required for the expression of MHC CLASS II GENES. It also binds to inverted repeats of HEPATITIS B VIRUS DNA and is required for viral gene expression. RFX1 functions as a monomer or heterodimer with other RFX transcription factors.

Synonyms: RFX1 Transcription Factor, RF-X Binding Protein, RFX Regulatory Factor, RFX1 Protein, MHC Class II Regulatory Factor RFX, RF X Binding Protein, 0, Regulatory Factor, RFX, Regulatory Factor X1, Regulatory Factor-X, Regulatory Factor X, X Box Binding Protein (RF-X), Transcription Factor, RFX1