May act as a scaffolding protein within caveolar membranes, functionally participating in formation of caveolae or caveolae-like vesicles. Heterooligomeric complex of flotillin-1 and flotillin-2 and caveolin-1 and caveolin-2. Identified by mass spectrometry in melanosome fractions from stage I to stage IV. Membrane-associated protein of caveola. Normally expressed in growing retinal exons of newly differentiated ganglion cells at the retinal margin. After optic nerve injury, expressed in all retinal ganglion cells and retinal axons. Also expressed in endothelial cells, spinal cord, larval and adult skin, muscle processes, thymus and gill macrophages. By optic nerve injury. Belongs to the band 7/mec-2 family. Flotillin subfamily.