Receptors are often considered as single entities in isolation from their local context. Receptors are, however, surrounded by many seemingly ‘invisible’ components of a human cell. Thousands of distinct molecules are crowded together:- neighbouring proteins, invaginations of the plasma membrane undergoing endocytosis, a myriad of intracellular avenues formed by the cytoskeleton or extensive glycan networks that establish the extracellular matrix (ECM). As well as being major ‘signalling hubs’, RTKs travel around cells via increasingly acidic vesicles following endocytosis. The dynamic nature of receptor trafficking will therefore expose RTKs to a range of distinct biochemical microenvironments. The Peach laboratory is interested in how the unique local microenvironment of a receptor modulates their pharmacology.