Illustration of the plasma membrane protein human Caveolin-1 (CAV1). This protein is required to generate membrane curvature in small invaginations of the cell plasma membrane known as caveolae. Caveolae regulate the movement of substances into a cell (endocytosis) and sense and respond to plasma membrane tension. CAV1 has been shown to regulate various chemical signalling pathways involved in cell growth, proliferation and differentiation.