SPIBTranscription factor Spi-B is a protein that in humans is encoded by the SPIB gene.FunctionSPI1 and SPIB are members of a subfamily of ETS transcription factors. ETS proteins share a conserved ETS domain that mediates specific DNA binding. SPIB and SPI1 bind to a purine-rich sequence, the PU box.InteractionsSPIB has been shown to interact with MAPK3 and MAPK8.