Cells in our body constantly interact with the surrounding environment obtaining nutrients and interacting with neighbor cells.

The cells and the extracellular space constitute the environment that determines the tissue function, cell differentiation, and healthiness of the cell. Interestingly, cells shape their extracellular matrix by actively synthesizing and secreting molecules into the extracellular space.

In the retina, the neuronal photoreceptors cells and the glial retina pigment epithelium (RPE) cells interact through a specialized extracellular matrix, the Interphotoreceptor matrix (IPM). Patients with mutations in molecules of the IPM develop blinding diseases.