TNIK is a MSN protein kinase that interacts with both TNF receptor-associated factor 2 (TRAF2) and the adapter protein NCK. The protein has been shown to activate the c-Jun N-terminal kinase pathway when over expressed in Phoenix-A cells. TNIK has been shown to phosphorylate gelsolin, the principal intracellular and extracellular actin-severing protein, in vitro. This and evidence from mutational studies suggest that TNIK functions in the regulation of the cytoskeleton. Northern analysis indicates TNIK expression in human heart, skeletal muscle, and brain, with lower levels of expression in kidney, liver, lung, and pancreas. ESTs have been isolated from human tissue libraries, including normal amnion, gallbladder and skin.