Sra1 is a functional RNA which acts as a transcriptional coactivator that selectively enhances steroid receptor-mediated transactivation ligand-independently through a mechanism involving the modulating N-terminal domain (AF-1) of steroid receptors. Sra1 also mediates transcriptional coactivation of steroid receptors ligand-dependently through the steroid-binding domain (AF-2).Sra1 enhances cellular proliferation and differentiation and promotes apoptosis in vivo. Sra1 may play a role in tumorigenesis.