spectrin

:  a large cytoskeletal protein that is found on the inner cell membrane of red blood cells and that functions especially in maintaining cell shape The erythrocyte cytoskeleton, which consists primarily of a meshwork of spectrin and actin, controls cell shape and the disposition of protein within the membrane.—Robert Siman et al., Nature, 17 Jan. 1985 A number of genetic diseases (hemolytic anemias) characterized by fragile, abnormally shaped erythrocytes have been traced to mutations in ankyrin or spectrin.—Gerald Karp, Cell and Molecular Biology: Concepts and Experiments, 6th edition, 2010