a ubiquitous transcription factor that binds to the octamer motif (5'-ATTTGCAT-3') and activates the promoters of the genes for some small nuclear RNAs (snRNA) and of genes such as those for histone H2B and immunoglobulins. Modulates transcription transactivation by NR3C1, AR and PGR. Phosphorylation apparently inhibits its interaction with DNA. Four splice variant isoforms have been described. Isoform 2 is lymphocyte specific. Note: This description may include information from UniProtKB.