Transcription factor

Protein that regulates the rate of DNA transcription

In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to DNA sequences. Specificity can be due to sequence motifs, or epigenetic modifications. The function of TFs is to regulate—turn on and off—genes in order to make sure that they are expressed in the desired cells at the right time and in the right amount throughout the life of the cell and the organism.

From Wikipedia, under CC BY-SA. More on occurri.