Tyrosine Kinase Inhibitors (TKIs) are a class of medications that block the action of enzymes called tyrosine kinases. These enzymes play a crucial role in the signaling pathways that regulate cell division and growth. By inhibiting these enzymes, TKIs can help prevent the uncontrolled cell proliferation seen in various types of cancer. TKIs are often used in the treatment of specific cancers, such as chronic myeloid leukemia and certain types of lung cancer. They target specific mutations or abnormalities in cancer cells, making them a more personalized treatment option. Common examples of TKIs include imatinib and erlotinib.