Transcription factors are defined as proteins that bind to specific DNA sequences to regulate the transcription of nearby genes. A typical transcription factor must contain the following: one or more DNA-binding domains which attach to specific enhancer or promoter regions; and a trans-activating domain that contains binding sites to other proteins or complexes. Stabilizing the DNA binding of RNA polymerase or causing the acetylation of histones results in gene upregulation. Inversely, blocking RNA polymerase binding causes downregulation. The transcription factor protein family is extremely broad; they are reported to comprise approximately 10% of human genes. Antibodies to transcription factor proteins are similarly abundant, but to help narrow down your search, simply fill in the search boxes or select the appropriate filters.