The TNIK gene codes for a member of the serine/threonine kinase of the Ste20 family of It belongs to the germinal center kinase subgroup of this family that is involved in cytoskeleton organization and neuronal dendrite extension.  It functions as a tumor suppressor by activation of the c-Jun N-terminal kinase (JNK) pathway, and is associated with Rap2 to regulate cytoskeleton organization and cell spreading.  It also localizes in the nuclei and functions as transcription activator of the Wnt signaling pathway in a β-catenin-dependent manner.  In addition, recent studies have hinted at a possible role as a scaffold that assembles molecular complexes for downstream signal transduction

Defects in this gene have been associated with colorectal cancer as well as a specific form of autosomal recessive mental retardation.  

The TNIK gene has been mapped to the 3q26.2-q26.3 chromosome.  It has 33 coding exons spanning about 399 kb within the genomic DNA.  The encoded protein comprises 1360 amino acids with a molecular weight of 155 kDa.  Like other members of the germinal center kinase (GCK) proteins family, TNIK is also characterized by the presence of an N-terminal kinase domain and a regulatory C-terminal GCK domain.  The protein is expressed ubiquitously, but maximum expression levels are seen in heart, brain and skeletal muscle cells, as well as in colorectal cancers.