The EF-hand domain is a twelve amino acid loop motif that is commonly found in proteins that participate in calcium-binding events within the cell. EF-hand domains generally exist in a pair that, together, form a stable four-helix bundle that enables the binding of calcium ions. MYL6 (myosin, light chain 6, alkali, smooth muscle and non-muscle), also known as ESMLC, LC17A, LC17B or MLC1SM, is a 151 amino acid protein that contains three EF-hand domains and exists as two alternatively spliced isoforms, designated smooth muscle (MLC3SM) and non-muscle (MLC3NM). Existing as an alkali light chain component of the hexameric Myosin complex, MYL6 participates in generating the force for cellular movements, thereby playing an important role in overall cellular function. The gene encoding MYL6 maps to human chromosome 12, which encodes over 1,100 genes and comprises approximately 4.5% of the human genome.