A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to a protein in a cell. It functions as an "on"or "off"switch in many cellular functions.

Tyrosine Kinase Activity and Transformation Potency of bcr-abl Oncogene Products
The fms-like tyrosine kinase, a receptor for vascular endothelial growth factor.
Signal transduction by receptors with tyrosine kinase activity.
Acquired mutation of the tyrosine kinase JAK2 in human myeloproliferative disorders.
Cell signaling by receptor tyrosine kinases: From basic concepts to clinical applications
mTOR Inhibition Induces Upstream Receptor Tyrosine Kinase Signaling and Activates Akt
Specificity of receptor tyrosine kinase signaling: transient versus sustained extracellular signal-regulated kinase activation
Efficacy and Safety of a Specific Inhibitor of the BCR-ABL Tyrosine Kinase in Chronic Myeloid Leukemia
Excess placental soluble fms-like tyrosine kinase 1 (sFlt1) may contribute to endothelial dysfunction, hypertension, and proteinuria...
Efficacy of gefitinib, an inhibitor of the epidermal growth factor receptor tyrosine kinase, in symptomatic patients with non-small ...