RUNX3 encodes a member of the runt domain-containing family of transcription factors. A heterodimer of this Runt-related transcription factor 3 and a beta subunit forms a complex that binds to the core DNA sequence 5′-PYGPYGGT-3′ found in a number of enhancers and promoters, and can either activate or suppress transcription. It also interacts with other transcription factors. It functions as a tumor suppressor, and the gene is frequently deleted or transcriptionally silenced in cancer. Alternative splicing results in multiple transcript variants.