Well, a liposome is basically this aqueous compartment that is surrounded by a bilayer, a membrane that consists of two layers of phospholipid molecules. So this is what it actually looks like. So it's kind of like a cell, except it's much smaller. And inside this compartment, we don't have organelles, the cell nucleus or anything like that, but we can put in special molecules, as we'll see in just a moment, like drugs or DNA into this compartment. And that can be delivered to cells of our body. So liposomes are relatively small, so about 50 nm in diameter acquisition compartments that are surrounded by phospholipid bilayer membrane.