MEFV is a human gene that provides instructions for making a protein called pyrin. Pyrin is produced in certain white blood cells that play a role in inflammation and in fighting infection. Inside these white blood cells, pyrin is found with the cytoskeleton, the structural framework that helps to define the shape, size, and movement of a cell. Pyrin's protein structure also allows it to interact with other molecules involved in fighting infection and in the inflammatory response. Although pyrin's function is not fully understood, it likely assists in keeping the inflammation process under control. Research indicates that pyrin helps regulate inflammation by interacting with the cytoskeleton. Pyrin may direct the migration of white blood cells to sites of inflammation and stop or slow the inflammatory response when it is no longer needed.