Transcription factor 7-like 2 (T-cell specific, HMG-box), also known as TCF7L2 or TCF4, is a protein acting as a transcription factor that, in humans, is encoded by the TCF7L2 gene. The TCF7L2 gene is located on chromosome 10q25.2–q25.3, contains 19 exons. As a member of the TCF family, TCF7L2 can form a bipartite transcription factor and influence several biological pathways, including the Wnt signalling pathway.
Single-nucleotide polymorphisms (SNPs) in this gene are especially known to be linked to higher risk to develop type 2 diabetes, gestational diabetes, multiple neurodevelopmental disorders including schizophrenia and autism spectrum disorder, as well as other diseases. The SNP rs7903146, within the TCF7L2 gene, is, to date, the most significant genetic marker associated with type 2 diabetes risk.