Receptor tyrosine kinases (RTKs) are a type of protein found on the surface of cells that play a crucial role in cell communication and growth. They are activated when specific molecules, known as ligands, bind to them. This binding triggers a series of chemical reactions inside the cell, leading to various cellular responses, such as division, differentiation, and survival. RTKs are important in many biological processes and are often implicated in diseases, including cancer. Abnormal activation or mutations in receptor tyrosine kinases can lead to uncontrolled cell growth, making them a target for specific cancer therapies. Understanding RTKs is essential for developing treatments that can effectively target these pathways.