SUPT5HTranscription elongation factor SPT5 is a protein that in humans is encoded by the SUPT5H gene. Together with hSPT4, it composes DSIF in humans.InteractionsSUPT5H has been shown to interact with: CDK9, Cyclin-dependent kinase 7, HTATSF1, PIN1, POLR2A, PRMT1 and Protein arginine methyltransferase 5.