Caveolin-1 is a palmitoylated 22kD membrane-associated protein in caveolae which are cholesterol-rich invaginations in the plasma membrane involved in vesicular transport and the regulation of lipid rafts and signal transduction. Caveolin-1 expression is dysregulated during cancer progression and exhibits both positive and negative effects on tumor progression. The central region of Caveolin-1 (aa105-125) is buried in the lipid layer, while the N- and C-terminal flanking regions are exposed to the cytoplasm and interact with many other proteins. Alternate splicing in human, mouse, and rat Caveolin-1 generates an isoform with a deletion of the N-terminal 31 residues.