tyrosine kinase non receptor 1(TNK1) Homo sapiens. The protein encoded by this gene belongs to the tyrosine protein kinase family. Tyrosine protein kinases are important regulators of intracellular signal transduction pathways, mediating cellular proliferation, survival, and development. This gene is highly expressed in fetal tissues and at lower levels in few adult tissues, thus may function in signaling pathways utilized broadly during fetal development, and more selectively in adult tissues. It plays a negative regulatory role in the Ras-Raf1-MAPK pathway, and knockout mice have been shown to develop spontaneous tumors, suggesting a role as a tumor suppressor gene. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2011],