TCF-9 (transcription factor 9), also known as C2orf3 (chromosome 2 open reading frame 3), GCF (GC-rich sequence DNA-binding factor) or DNABF, is a 781 amino acid nuclear protein that belongs to the GCF family. Widely expressed, GCF binds the GC-rich sequences of beta-Actin, EGFR and calcium-dependent protease (CANP) promoters. GCF contains multiple phosphoserine and phosphothreonine residues, and two GCF isoforms are produced due to alternative splicing events. GCF is considered a candidate for susceptibility to dyslexia (DYX3) as both genes reside in close proximity on human chromosome 2. Chromosome 2 is the second largest human chromosome and consists of 237 million bases, encodes over 1,400 genes and makes up approximately 8% of the human genome.