Transcription factor SP1 (SP1) is a transcription factor that can activate or repress transcription in response to physiological and pathological stimuli. SP1 binds with high affinity to GC-rich motifs and regulates the e, Xenopus/Amphibian,pression of a large number of genes involved in a variety of processes such as cell growth, apoptosis, differentiation and immune responses. SP1 is highly regulated by post-translational modifications (phosphorylations, sumoylation,Porcineroteolytic cleavage, glycosylation and acetylation).