SPI1 encodes an ETS-domain transcription factor that activates gene expression during myeloid and B-lymphoid cell development. The nuclear protein binds to a purine-rich sequence known as the PU-box found near the promoters of target genes, and regulates their expression in coordination with other transcription factors and cofactors. The protein can also regulate alternative splicing of target genes. Multiple transcript variants encoding different isoforms have been found for this gene.SPI1 (Spi-1 Proto-Oncogene) is a Protein Coding gene. Diseases associated with SPI1 include Inflammatory Diarrhea and Interdigitating Dendritic Cell Sarcoma. Among its related pathways are Validated targets of C-MYC transcriptional repression and C-MYB transcription factor network. GO annotations related to this gene include transcription factor activity, sequence-specific DNA binding and RNA binding. An important paralog of this gene is SPIB.