**6.4 Receptor tyrosine kinase inhibitors (TKIs)**

Several small molecule inhibitors of VEGF receptor tyrosine kinase activity now have an established role in the treatment of certain tumour types, including mRCC, HCC and advanced CRC. These small molecule inhibitors readily diffuse through the cell membrane to compete for ATP binding to the intracellular tyrosine kinase domain of VEGF receptor 2.
