Desmin is a 53 kDa muscle -specific molecule, which belongs to the middle silk super family of cell skeleton protein. Cyclical protein digosum formation forms a stable wire -shaped network, which can stabilize the horizontal arrangement of the muscle fiber. Most mutations affect filament assembly. Desmin knockout mice will form myocardial disease, skeletal muscle defects and smooth muscle defects. It is a good screening symbol of tumor with muscle -derived differentiation, including transverse muscle sarcoma, horizontal fibroids, smooth muscle sarcoma, smooth fibroids, smooth muscles, and horizontal muscle cells in other tumors.