Flotillins belong to a family of lipid raft-associated integral membrane proteins that carry a evolutionarily conserved domain called the prohibitin homology domain (PHB). Flotillin members are ubiquitously expressed and located to non-caveolar microdomains (lipid rafts) on the cell plasma membrane where they support signal transduction and regulate lipid raft motility and localization. Two flotillin members have been described, flotillin-1 and flotillin-2. In addition to its colocalization with lipid rafts on the plasma membrane, flotillin-1 also has been found at compartments of the endocytic and autophagosomal pathways, such as recycling/late endosomes, the Golgi complex, as well as the nucleus. Flotillin-2 is mainly localized to the plasma membrane and is prevalent in cell-cell contact sites. However, overexpressed flotillin-2 has also been found in the late endosome. Both flotillin-1 and flotillin-2 are commonly used as lipid raft associated markers.