A common element of lipid droplets is perilipin 2/adipophilin/ADRP/PLIN2. It is inducible by etomoxir and has been detected on the surface of lipid droplets in a variety of cultured cell lines as well as in the membranes of milk fat globules. For diseases with elevated lipid droplet accumulation, elevated expression of Perilipin 2/Adipophilin/ADRP/PLIN2 is a helpful marker. These conditions include obesity, steatosis, atheroma, and some types of liposarcoma. It appears to be a strong indicator of atherosclerosis as well. Viral entrance through lipid droplets can also be investigated using ADRP.