The function of SP3 (Sp3 transcription factor, Ensembl gene identifier ENSG00000172845) is as follows. Transcriptional factor that can act as an activator or repressor depending on isoform and/or post-translational modifications. Binds to GT and GC boxes promoter elements. Competes with SP1 for the GC-box promoters. Weak activator of transcription but can activate a number of genes involved in different processes such as cell-cycle regulation, hormone-induction and house-keeping. {ECO:0000269|PubMed:10391891, ECO:0000269|PubMed:11812829, ECO:0000269|PubMed:12419227, ECO:0000269|PubMed:12837748, ECO:0000269|PubMed:15247228, ECO:0000269|PubMed:15494207, ECO:0000269|PubMed:15554904, ECO:0000269|PubMed:16781829, ECO:0000269|PubMed:17548428, ECO:0000269|PubMed:18187045, ECO:0000269|PubMed:18617891, ECO:0000269|PubMed:9278495}.