Anti-myosin light chain 4 antibodies are used in the immunodetection of the protein encoded by the MYL4 gene. In humans, the canonical protein has a reported length of 197 amino acid residues and a mass of 21.6 kDa. The myosin light chain 4 protein is involved with muscle contraction, among other functions. Other names for this target antigen include AMLC, GT1, PRO1957, atrial myosin light chain 1, myosin, atrial/fetal muscle, light chain, and ALC1.