MYLK also known as MLCK is a muscle member of the immunoglobulin gene superfamily, encodes myosin light chain kinase which is a calcium/calmodulin dependent enzyme. MYLK protein plays a crucial role in muscle contraction by phosphorylating myosin regulatory light chains, which facilitates interaction between myosin and actin filaments, leading to contractile activity. This function is particularly important in smooth muscle tissues, where MYLK isoforms contribute to regulation of vascular tone and gastrointestinal motility. MYLK gene encodes several isoforms, including those specific to smooth muscle and non-muscle tissues, as well as telokin, a small isoform that stabilizes unphosphorylated myosin filaments. Multiple transcript variants for MYLK gene highlight diverse regulatory roles across different tissues.