LMOD1 (Leiomodin 1) is an actin nucleator protein that plays a critical role in smooth muscle cell function and contractility. LMOD1 is required for proper contractility of visceral smooth muscle cells and mediates nucleation of actin filaments 1. The protein is preferentially expressed in vascular and visceral smooth muscle cells and is regulated by the serum response factor (SRF)/myocardin transcriptional pathway 2. LMOD1 contains two actin-binding sites (ABS2) that are essential for both protein stability and actin nucleation function 3. Loss-of-function mutations in LMOD1 cause megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS) and pediatric intestinal pseudo-obstruction, resulting in impaired smooth muscle contractility, reduced filamentous actin, and elongated cytoskeletal dense bodies 13. LMOD1 is also a coronary artery disease risk gene, where genetic variants affecting LMOD1 expression contribute to vascular smooth muscle cell dysfunction and atherosclerosis development 45. In vascular smooth muscle cells, LMOD1 helps maintain the differentiated phenotype and prevents excessive proliferation and migration 4.