A drug that blocks the effects of a protein called tyrosine kinase, which is involved in new blood vessel growth essential for cancer cells to divide and grow. These treatments starve the tumour by stopping the development of a new blood supply (angiogenesis). Doctors call treatments that interfere with the development of a blood supply anti-angiogenic agents. Tyrosine kinase inhibitors also interfere with the growth of cancer cells by blocking the signals within the cancer cells that tell them to grow and divide, causing the cancer cells to die. Examples of TKIs include sunitinib (Sutent), sorafenib (Nexavar), pazopanib (Votrient), and axitinib (Inlyta).