Transcription factors are proteins that that bind to specific DNA sequences, thereby regulating the transcription of genetic information from DNA to mRNA. Transcription factors regulate RNA polymerase activity on specific genes alone or with other proteins in a complex, as an activator or repressor. Approximately 10% of genes in the genome code for transcription factors, which makes this family the single largest family of human proteins. Transcription factors regulate various processes in living organisms, such as growth and development, differentiation, morphogenesis and transformation.