Actin-related proteins are classified into Arp subclasses according to their amino acid sequence similarity to Actin. Both Arps and Actin proteins have an ATPase domain, which catalyzes the decomposition of adenosine triphosphate (ATP) into adenosine diphosphate (ADP) and a free phosphate ion to release energy. ArpM1 (actin-related protein M1) is a 372 amino acid ubiquitously expressed protein that localizes to both the cytoplasm and the cytoskeleton and belongs to the Arp family of Actin-like proteins. The gene encoding ArpM1 maps to human chromosome 3, which houses over 1,100 genes, including a chemokine receptor (CKR) gene cluster and a variety of human cancer-related gene loci.