Members of the Leiomodin protein family are closely related to the tropomodulin family of actin filament pointed end-capping proteins. Leiomodins are actin-binding proteins that act as strong filament nucleators in muscle cells. Leiomodin 1 is highly expressed in a variety of tissues that contain smooth muscle, therefore it is also known as smooth muscle Leiomodin, or SM-Lmod. Also designated C-Lmod, Leiomodin 3 is found in several types of fetal tissue and is involved in tropomyosin binding. Leiomodin 2, also known as C-LMOD or LMOD2, is a 547 amino acid protein that is specifically expressed in heart and skeletal muscles. Leiomodin 2 binds to tropomyosin and may block the elongation and depolymerization of actin filaments at their pointed end. Leiomodin 2 is encoded by a gene that is located near the hypertrophic cardiomyopathy locus CMH6 on chromosome 7, suggesting that Leiomodin 2 may be involved in that disease process. Leiomodin 2 is expressed as three alternatively spliced variants.